Skocz do pozycji: 1.

Tytuł:

Proton and Deuteron Relaxation Study of Molecular Dynamics in Lysozyme Solutions

Autorzy:

Kakule, J. F.
Węglarz, W. P.
Shenoy, R. K.
Sharp, A. R.
Peemoeller, H.

Powiązania:

https://bibliotekanauki.pl/articles/2014096.pdf

Data publikacji:

2000-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

76.60.-k
87.15.-v

Opis:

A nuclear magnetic resonance spin-lattice relaxation dispersion study of the relaxation of several magnetization components in both natural and deuterated lysozyme solutions was undertaken at 20°C. Proton and deuteron resonances were employed. The two-dimensional time evolution of the magnetization and the spin-spin relaxation were analyzed. In addition, an isotopic dilution study was performed at 5 and 30.6MHz. The results indicate that the water proton spin-lattice relaxation rate which arises from intermolecular relaxation between the water protons and the lysozyme protons represents a relatively strong relaxation mechanism. A model for the dynamics of the water molecules, consistent with the proton and deuteron dispersions as well as with the isotopic dilution results, is presented.

Źródło:

Acta Physica Polonica A; 2000, 98, 1-2; 131-152
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 2.

Tytuł:

Phase Space as Arena for Atomic Motion in a Quantized Light Field

Autorzy:

Mayr, E.
Krähmer, D.
Herkommer, A. M.
Akulin, V. M.
Schleich, W. P.
Averaukh, I. Sh.

Powiązania:

https://bibliotekanauki.pl/articles/1931421.pdf

Data publikacji:

1994-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.50.Wm
42.50.Vk

Opis:

We describe the motion of an atom in a quantized light field using the concept of the Wigner distribution in phase space. This approach provides a pictorial explanation of the deflection and focusing of the atomic beam.

Źródło:

Acta Physica Polonica A; 1994, 86, 1; 81-95
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Superconductivity in Indium Diffused GaAs

Autorzy:

Baranowski, J. M.
Wójcik, P.
Palczewska, M.
Jabłoński, R.
Weber, E. R.
Yau, W. P.
Sohn, H.
Werner, P.

Powiązania:

https://bibliotekanauki.pl/articles/1921582.pdf

Data publikacji:

1992-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

74.70.Mq
76.20.+q

Opis:

Superconductivity of indium diffused GaAs was investigated. The superconductivity in these samples was identified by the magnetic susceptibility and the characteristic field modulated microwave absorption. The static magnetic susceptibility was measured from 40 K down to 2.5 K. The result shows two distinctive diamagnetic contributions within 7 K-2.5 K range. These diamagnetic contributions were correlated with the excess of In and Ga metal in GaAs.

Źródło:

Acta Physica Polonica A; 1992, 82, 4; 670-673
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Collective Spontaneous Emission from a System of Quantum Dots

Autorzy:

Abdussalam, W.
Machnikowski, P.

Powiązania:

https://bibliotekanauki.pl/articles/1403617.pdf

Data publikacji:

2012-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.67.Hc
42.50.Ct
03.65.Yz

Opis:

We study the spontaneous emission from a regular lateral array or a randomly distributed ensemble of quantum dots under strong excitation (full inversion) conditions. We focus on the similarities and differences between the cases of random and regular arrangement of the dots and show that there is very little difference between the evolution of luminescence in these two cases, both for identical dots and for a realistically inhomogeneously broadened ensemble. This means that the enhanced emission or superradiance effect is not due to accidental clustering of pairs of dots. Moreover, we point out that observation of an enhanced emission under weak excitation does not prove that true superradiance will develop in a fully inverted system.

Źródło:

Acta Physica Polonica A; 2012, 122, 6; 994-996
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Collective Spontaneous Emission from Pairs of Quantum Dots: Long-Range vs. Short-Range Couplings

Autorzy:

Abdussalam, W.
Machnikowski, P.

Powiązania:

https://bibliotekanauki.pl/articles/1492857.pdf

Data publikacji:

2011-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.67.Hc
42.50.Ct
03.65.Yz

Opis:

We study the spontaneous emission from a coherently delocalized exciton state in a double quantum dot as a function of the distance between the dots, focusing on the similarities and differences between the cases of radiative (long-range, dipole) and tunnel coupling between the excitons in the dots. We show that there may be no qualitative difference between the collective emission induced by these two coupling types in spite of their essentially different physical properties.

Źródło:

Acta Physica Polonica A; 2011, 120, 5; 865-867
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

New Method of Uncertainty Evaluation of the Sound Insulation of Partitions

Autorzy:

Batko, W.
Pawlik, P.

Powiązania:

https://bibliotekanauki.pl/articles/1400075.pdf

Data publikacji:

2013-06

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

43.55.-n
43.55.+p

Opis:

The analysis of uncertainty related to evaluation of sound insulation of partitions performed according to standard solutions recommended in The Guide to the Expression of Uncertainty in Measurement (GUM) by ISO/IEC-1998 and according to the new method based on the interval analysis - is presented in the paper. Both methods are compared and their application advantages presented. Limitations of the current solutions based on the law of propagation of uncertainty are shown. The method of the estimate derivation for the sound insulation based on interval arithmetic related to the measurement data is presented. The influence of the input parameters uncertainty on the calculation results of the sound insulation of partitions is determined. The considerations are illustrated by numerical examples.

Źródło:

Acta Physica Polonica A; 2013, 123, 6; 1012-1015
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

Investigation of the Spin-Orbit Perturbation of the 6¹Π State in KLi Molecule

Autorzy:

Jastrzebski, W.
Kowalczyk, P.

Powiązania:

https://bibliotekanauki.pl/articles/1812037.pdf

Data publikacji:

2008-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

33.15.-e
33.20.Vq
31.50.Df
31.50.Gh

Opis:

Strong perturbation in the 6¹Π state of the ³⁹K⁷Li molecule is analysed. The perturbing state is identified as 3³∆ on the basis of experimental observations aided by comparison with recent theoretical calculations. Possibilities of accessing triplet states of KLi via the 6¹Π∼ 3³∆ perturbation are discussed.

Źródło:

Acta Physica Polonica A; 2008, 114, 4; 731-738
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

Nonfrustrated Antiferromagnet in a Frustrated Lattice Due to Charge Ordering: A Scenario for Pairing in Layered Cobaltates

Autorzy:

Wróbel, P.
Suleja, W.

Powiązania:

https://bibliotekanauki.pl/articles/2047314.pdf

Data publikacji:

2007-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.10.Fd
74.20.Mn
75.50.Ee

Opis:

The mechanism of pairing-symmetry selection in the weakly electron doped t-J model on the honeycomb lattice has been analyzed. The discussion of that problem has been motivated by some recent suggestions that due to charge ordering which may take place in the unconventional superconductor Na$\text{}_{x}$CoO$\text{}_{2}$· yH$\text{}_{2}$O at doping levels near x=1/3 the physics of CoO$\text{}_{2}$ planes may be effectively described in terms of a model for a weakly electron doped antiferromagnet on the honeycomb lattice. In the current publication the main emphasis has been put on reviewing experimental and theoretical work, the results of which support the scenario of charge order. In the calculation, the so-called string picture has been used. It has been demonstrated that spin fluctuations may induce in the honeycomb lattice the formation of an unconventional two-particle bound state. Upon the condensation of bound particles this mechanism may give rise to unconventional pairing. The critical value of the ratio J/t which is sufficient to induce binding has not been evaluated. It has been assumed instead that in the case of cobaltates some additional isotropic attractive interaction, for example phonon mediated, is active. Despite that the exchange of spin fluctuations is not a dominating interaction, it selects the symmetry of the paired state because it is anisotropic. C$\text{}_{3v}$ is the relevant point group for the t-J model on the honeycomb lattice. It has been shown that the bound state of two additional electrons doped to the half-filled antiferromagnetically ordered system has zero total momentum and p-wave symmetry of the irreducible representation E. The expected paired state is a mixture of a singlet and a triplet because the honeycomb lattice does not possess the inversion symmetry.

Źródło:

Acta Physica Polonica A; 2007, 111, 4; 563-572
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

Polarisation Labelling Spectroscopy of Highly Excited (Rydberg) $\text{}^{1}$Π$\text{}_{u}$ States in Potassium Dimer

Autorzy:

Jastrzebski, W.
Kowalczyk, P.

Powiązania:

https://bibliotekanauki.pl/articles/2043661.pdf

Data publikacji:

2005-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

31.50.Df
33.20.Lg
33.20.Vq

Opis:

Two previously unknown electronic states of K$\text{}_{2}$, both of $\text{}^{1}$Π$\text{}_{u}$ symmetry, have been observed by polarisation labelling spectroscopy technique in the energy region of 31500-33100 cm$\text{}^{-1}$ above the bottom of the molecular ground state potential well. Major molecular constants have been determined for these states and the potential curves have been constructed using the Rydberg-Klein-Rees method. The correlation of the observed states with atomic limits is discussed.

Źródło:

Acta Physica Polonica A; 2005, 108, 3; 457-465
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 10.

Tytuł:

Oblique Reflection of Electrons from a Potential Barrier in Heterostructures

Autorzy:

Pfeffer, P.
Zawadzki, W.

Powiązania:

https://bibliotekanauki.pl/articles/1205321.pdf

Data publikacji:

2014-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.70.Ej
73.22.Dj
73.40.-c
75.76.+j

Opis:

Reflection of electrons from a potential barrier in heterostructures is described. An electric field of the barrier causes spin splitting of electron energies via the spin-orbit interaction and its form is calculated in the three-level $k·p$ model for a nontrivial case of unbound electrons. It is shown that if the potential barrier is the only source of the spin-orbit interaction, the spin-flip electron reflections are not possible. However, there appear two unexpected possibilities related to the spin-orbit interaction: (a) non-attenuated electron propagation in the barrier whose height exceeds the energies of incoming electrons, (b) total reflection of electrons whose energies exceed barrier's height. It is indicated that the system can serve as a source of spin-polarized electron beams.

Źródło:

Acta Physica Polonica A; 2014, 126, 3; 820-826
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

Phonon-Assisted Electronic Transport through Double Quantum Dot System Coupled to Ferromagnetic Leads

Autorzy:

Trocha, P.
Rudziński, W.

Powiązania:

https://bibliotekanauki.pl/articles/1399105.pdf

Data publikacji:

2013-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

72.25.Mk
73.23.Hk
73.63.Kv

Opis:

Phonon-assisted electronic tunneling is studied through a double quantum dot coupled in parallel to ferromagnetic electrodes. The current-voltage characteristics for the system are derived within the nonequilibrium Green function technique based on equation of motion. It is found that additional phonon-induced resonance peaks appear in the spectral function on both sides of the main resonances corresponding to the quantum dot energy levels. It is shown that the "molecular-like" resonances are reproduced in the phonon side bands in the differential conductance. A significant phonon-induced enhancement of tunnel magnetoresistance as well as tunnel magnetoresistance oscillations are also predicted.

Źródło:

Acta Physica Polonica A; 2013, 124, 5; 843-845
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 12.

Tytuł:

Uncertainty Evaluation in Modelling of Acoustic Phenomena with Uncertain Parameters Using Interval Arithmetic

Autorzy:

Batko, W.
Pawlik, P.

Powiązania:

https://bibliotekanauki.pl/articles/1490309.pdf

Data publikacji:

2012-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

43.28.Lv
43.55.Br

Opis:

Uncertainty assessment in modelling of acoustic phenomena with uncertain parameters using interval arithmetic on the example of the reverberation time estimation, are presented in the paper. The application of the classical interval analysis formalism as well as its expansions are shown. Statistical methods of estimation of the reverberation time are based on parameters, which are related, among others, to the geometry of the analysed room, characteristics of sound absorption, and interior transmission. Values of these parameters are usually difficult to determine, which has a significant influence on the modelling result. The interval analysis allows to determine the variability interval of the parameter being estimated. The authors determined the influence of the input parameters uncertainty on the estimated reverberation time, calculated according to the Sabine, Eyring-Norris and Millington-Sette formulae. The uncertainty analysis was performed for the literature data, related to the reverberation time calculations of the room of a certified acoustics.

Źródło:

Acta Physica Polonica A; 2012, 121, 1A; A-152-A-155
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 13.

Tytuł:

Pairing-Symmetry Selection in a Weakly Doped Canted Antiferromagnet on the Triangular Lattice

Autorzy:

Wróbel, P.
Suleja, W.

Powiązania:

https://bibliotekanauki.pl/articles/1812329.pdf

Data publikacji:

2008-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.10.Fd
74.20.Mn
75.50.Ee

Opis:

The mechanism of superconductivity generation by spin fluctuations in the electron doped canted antiferromagnet on the triangular lattice was analyzed. The underlying assumption is that the formation of the bound state is the prerequisite of pairing. The outcome of this analysis is also valid if an additional isotropic attraction is active but the anisotropic spin-fluctuation mediated force decides on the symmetry of the two-particle bound state. When the canted antiferromagnetic state is generated, the symmetry of the point group $C_{6v}$ for the triangular lattice is lowered to the symmetry of $C_{3v}$. It is demonstrated that spin fluctuations definitely favor the p-wave bound state, which transforms according to the E representation of $C_{3v}$. Since the inversion is not an element of $C_{3v}$, the parity is not a good quantum number and thus the predicted paired state will be a mixture of singlet and triplet. Such a scenario may be relevant to physics of superconducting triangular cobaltates or organics.

Źródło:

Acta Physica Polonica A; 2008, 114, 1; 225-228
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Universal Ultrasonic Generator for Welding

Autorzy:

Kardyś, W.
Milewski, A.
Kogut, P.
Kluk, P.

Powiązania:

https://bibliotekanauki.pl/articles/1399360.pdf

Data publikacji:

2013-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.20.Vj
43.35.-c
43.35.+d
77.65.Dq
77.84.Cg
85.50.-n

Opis:

The paper presents design and parameters of a multifunction ultrasonic generator manufactured by Tele and Radio Research Institute. Efficient usage of ultrasonic welding and cutting technology depends on the ability to precisely control process parameters and tune those parameters to suit particular needs. Ultrasonic generator is responsible for such control and tuning. Presented design incorporates powerful 32 bit Cortex M4 microcontroller with floating point unit which allows using modern signal processing methods to calculate parameters of ultrasonic stack in real time. Calculated parameters, especially impedance of the stack are used to estimate load level and identify phases of the welding process such as melting of the welded material. Precise control of the output signal is possible due to innovative design of the direct digital signal synthesis unit implemented in programmable logic device (CPLD). Resonant inverter topology of the generator front end ensures high electrical efficiency of the device. Designed generator is equipped with various communication interfaces such as USB host and slave, Ethernet, Bluetooth, CAN and RS485. Multiple digital inputs and outputs together with load cell interface, 4-20 mA receiver and 0-10 V analog input enable the generator to monitor and control entire ultrasonic welding system without the need of a PLC unit.

Źródło:

Acta Physica Polonica A; 2013, 124, 3; 456-458
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Measurement System for Parameter Estimation and Diagnostic of Ultrasonic Transducers

Autorzy:

Kluk, P.
Milewski, A.
Kardyś, W.
Kogut, P.
Michalski, P.

Powiązania:

https://bibliotekanauki.pl/articles/1399367.pdf

Data publikacji:

2013-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

43.35.-c
43.35.+d
43.38.+n
43.38.-p
84.37.+q
07.10.-h
46.40.-f
07.20.Dt

Opis:

The paper presents an architecture and design of measurement system and methods for parameter estimation and diagnostic of ultrasonic transducers used in ultrasonic welding and cutting systems manufactured by Tele and Radio Research Institute. The key element of the ultrasonic welding and cutting system is a high power ultrasonic transducer implemented as a sandwich transducer consisting of a stack of piezoelectric ceramic rings mounted between two masses. High quality welding and cutting demand predetermined frequency characteristic of transducer impedance. Also important are: high energy efficiency, high coupling coefficient, low dielectric loss, and the optimal radiation pattern. In order to manufacture high quality and long-life transducers the piezoelectric rings must be selected and the sandwich transducers diagnosed on the basis of their measured parameters. Presented measurement system takes advantage of the virtual instrument technique in the NI LabVIEW environment. It uses Agilent U2761A Function Generator, U2531A Data Acquisition Unit, and the linear amplifier to measure impedance frequency characteristic in the frequency range of 10 kHz to 100 kHz. Moreover, the system can measure the vibration amplitude in the range of 1 μm up to 100 μm, using an optical sensor, and the temperature of the transducer using a pyrometer sensor.

Źródło:

Acta Physica Polonica A; 2013, 124, 3; 468-470
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

New Multimode Sonotrodes Models Designed for Rotary Ultrasonic Welding Systems

Autorzy:

Kogut, P.
Milewski, A.
Kardyś, W.
Kluk, P.
Gawryś, P.

Powiązania:

https://bibliotekanauki.pl/articles/1399374.pdf

Data publikacji:

2013-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

43.40.-r
43.40.+s
43.35.+d
43.38.+n
43.38.-p
46.40.-f

Opis:

The paper presents methods of designing sonotrodes, working in varied mechanical vibration modes in high power application regime such as rotary ultrasonic welding systems. The aim of the sonotrode design process is to optimize its shape to achieve the best energy efficiency for a given welding process. Sonotrode geometry influences the power transferred to the welded element because it determines the vibration amplitude distribution in the sonotrode. The most popular applications use sonotrodes designed for axial vibration. Conducted research have shown that the optimal displacement and strain distribution is achieved for sonotrodes working in various vibration modes such as axial, transverse, radial or their compositions. In the paper examples of multimode sonotrode models for various rotary ultrasonic welding technologies have been presented.

Źródło:

Acta Physica Polonica A; 2013, 124, 3; 474-478
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

New Method for Studying Biaxial Deformation Effects on Optical Spectra of Quantum Wells

Autorzy:

Sosin, T. P.
Trzeciakowski, W.

Powiązania:

https://bibliotekanauki.pl/articles/1931925.pdf

Data publikacji:

1995-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.66.Fd
73.20.Dx

Opis:

The effects of large deformation were studied by preparing thin (20-30 μm) membranes with quantum-well layers on top. A small gas pressure of a few bar deforms the membrane substantially and changes the optical spectra of the quantum wells. We present the results of the photoluminescence and absorption from GaAs/AlGaAs and from InGaAs/GaAs quantum wells subjected to tensile and to compressive biaxial strain. The light-hole lines shift more than two times faster than the heavy-hole lines so that they cross under tensile strain.

Źródło:

Acta Physica Polonica A; 1995, 87, 1; 151-156
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Interband Absorption in InGaAs/GaAs Quantum Well at High Hydrostatic Pressure

Autorzy:

Sosin, T. P.
Perlin, P.
Trzeciakowski, W.
Tober, R.

Powiązania:

https://bibliotekanauki.pl/articles/1929745.pdf

Data publikacji:

1993-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.20.Dx

Opis:

The interband absorption of strained InGaAs/GaAs multiple quantum well was studied at room temperature for pressures up to 5.5 GPa. Three absorption lines were attributed to the excitonic transitions hh1-e1, lh1-e1 and hh2-e2. They were visible until pressure of about 5 GPa which is above the Γ-X crossover for this system. Pressure coefficients of the observed lines were compared with the literature data. The origin of broadening of the lines above Γ-X crossover is discussed.

Źródło:

Acta Physica Polonica A; 1993, 84, 4; 749-752
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

Structural Properties of Co and CoFe Electrodes Forming a Magnetic Tunnel Junction

Autorzy:

Gładczuk, L.
Pankowski, P.
Paszkowicz, W.
Dłużewski, P.
Wójcik, M.
Przysłupski, P.

Powiązania:

https://bibliotekanauki.pl/articles/2047237.pdf

Data publikacji:

2007-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.15.Hi
68.65.Ac
61.10.Nz
76.60.Lz
68.37.Lp

Opis:

The M$\text{}_{1}$/MgO/M$\text{}_{2}$ trilayer tunnel magnetoresistance systems are studied by means of X-ray diffraction, NMR, and transmission electron microscopy techniques. As M$\text{}_{1}$ and M$\text{}_{2}$ electrodes we used Co, Fe, and CoFe layers. The growth mechanism and structural quality of both electrodes and of the epitaxial MgO barrier forming the magnetic tunnel junctions are experimentally examined. It is shown that the crystallographic coherence of magnetic tunnel junctions across the MgO barrier is significantly disturbed by imperfect crystal structure of magnetic electrodes. The NMR results indicate a difference in short-range order between bottom and top electrodes.

Źródło:

Acta Physica Polonica A; 2007, 111, 1; 135-140
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

Scanning Tunneling Microscopy/Spectroscopy Investigations of the Interference Effects Caused by the Circular Pits on the Thermally Oxidized graphite Surface

Autorzy:

Klusek, Z.
Kalinowski, M. W.
Olejniczak, W.
Kobierski, P.

Powiązania:

https://bibliotekanauki.pl/articles/1968772.pdf

Data publikacji:

1998-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

33.60.Fy
61.16.Ch
71.20.-b

Opis:

The thermal oxidation of the graphite leads to the removal of monoatomic carbon layers from the surface and formation of circular pits on the exposed plane. Near the pit edges the scanning tunneling spectroscopy measurements show a series of very narrow flat regions on the I/V characteristics. The observed I/V flat regions appear only when the characteristic is recorded very close to the pit edges. The appearance of tunneling current steps can be explained by the oscillating character of the local density of states near the pit edges. A simple quantum mechanical model in 2D based on boundary condition for an electron wave function is proposed.

Źródło:

Acta Physica Polonica A; 1998, 93, 2; 415-420
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

Charge Ordering and Phase Separations in the Molecular Crystal Model

Autorzy:

Czart, W.
Grzybowski, P.
Robaszkiewicz, S.

Powiązania:

https://bibliotekanauki.pl/articles/1537090.pdf

Data publikacji:

2010-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.10.Fd
71.30.+h
71.45.Lr
64.75.Gh

Opis:

We analyse the ground state phase diagrams and thermodynamic properties of charge orderings in narrow band materials using the molecular crystal model in the static limit. We present results for the hypercubic lattices in dimensions d = 2 and d = ∞. We focus our study on the problem of phase separations involving charge orderings and the effects of next-nearest-neighbor hopping $(t_2)$ on the charge ordered states in these systems. The ground state phase diagrams are evaluated for a few representative cases. Results for the molecular crystal model are compared with those obtained previously for the spinless fermion model with repulsive intersite interaction W.

Źródło:

Acta Physica Polonica A; 2010, 118, 2; 369-372
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Excitonic Molecule in Wurtzite Crystals

Autorzy:

Ungier, W.
Janiszewski, P.
Suffczyński, M.

Powiązania:

https://bibliotekanauki.pl/articles/1931241.pdf

Data publikacji:

1994-03

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.35.+z

Opis:

We calculate with the variational technique the fine structure of a biexciton in wurtzite crystals with the effective electron-hole exchange interaction taken into account. The values of the electron-hole exchange integrals are taken from the free exciton Γ$\text{}_{5}$-Γ$\text{}_{6}$ splitting. We calculate the biexciton dissociation energy and the ratio of mixing of the symmetric and antisymmetric envelopes which arises from the electron-hole exchange interaction. Results are presented for CdS, CdSe and ZnS crystals.

Źródło:

Acta Physica Polonica A; 1994, 85, 3; 607-613
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Survey of Industrial Applications of Conducting Polymers

Autorzy:

Roth, S.
Graupner, W.
McNeillis, P.

Powiązania:

https://bibliotekanauki.pl/articles/1932275.pdf

Data publikacji:

1995-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

72.80.Le
81.90.+c
89.20.+a

Opis:

Seventeen years after the first publication of doped polyacetylene we have already seen the appearance and disappearance of commercial products based on conducting polymers. In the present report we want to summarize the status quo in this field paying attention to existing products, laboratory demonstration set-ups and promising concepts.

Źródło:

Acta Physica Polonica A; 1995, 87, 4-5; 699-711
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Direct Two-Photon Creation of Excitonic Molecule in CuCl

Autorzy:

Ungier, W.
Janiszewski, P.
Suffczyński, M.

Powiązania:

https://bibliotekanauki.pl/articles/2014354.pdf

Data publikacji:

2000-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.35.-y

Opis:

The probability of direct excitation of excitonic molecule in the two-photon absorption process is calculated with an Hylleraas-Ore type biexciton envelope, which is variationally optimized. In the second order of perturbation, because of the resonance effect, only the exciton Γ$\text{}_{5}$ intermediate state is taken into account. The band structure at band extrema due to spin-orbit interaction is assumed. The transition probability of two-photon absorption is expressed by matrix element between the free exciton and the biexciton envelopes. The obtained probability of two-photon absorption in CuCl is about three orders of magnitude smaller when compared to that obtained by Hanamura.

Źródło:

Acta Physica Polonica A; 2000, 98, 4; 411-417
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Correlated Fermions Close to Mott Localization: Deviations from Landau Fermi-Liquid Picture

Autorzy:

Spałek, J.
Wójcik, W.
Korbel, P.

Powiązania:

https://bibliotekanauki.pl/articles/1964564.pdf

Data publikacji:

1997-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.27.+a
71.30.+h
71.10.Fd

Opis:

We summarize the main novel features of almost localized fermions in the presence of au applied magnetic field: (i) the spin dependence of their effective mass, which leads to quantum beats in the de Haas-van Alphen effect and (ii) the presence of a nonlinear molecular field and related metamagnetic behavior.

Źródło:

Acta Physica Polonica A; 1997, 92, 2; 277-280
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 26.

Tytuł:

Effect of Accumulation Layer on Tunneling in ZnSe-ZnTe Double Barrier Heterostructures

Autorzy:

Bała, P.
Ryszewski, R.
Bała, W.

Powiązania:

https://bibliotekanauki.pl/articles/1872642.pdf

Data publikacji:

1995-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

03.65.-w
73.40.Gk

Opis:

The tunneling probability in double barrier heterostructures can be affected by various effects. One of the most significant is presence of the accumulation layer placed before the structure. The presented time-dependent results show that charge trapped in the accumulation region oscillates in the triangular quantum well and tunnels sequentially through the double barrier structure resulting in periodical changes of the charge density right to the heterostructure.

Źródło:

Acta Physica Polonica A; 1995, 87, 2; 341-344
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

Lattice Parameter of Polycrystalline Diamond in the Low-Temperature Range

Autorzy:

Paszkowicz, W.
Piszora, P.
Łasocha, W.
Margiolaki, I.
Brunelli, M.

Powiązania:

https://bibliotekanauki.pl/articles/1538949.pdf

Data publikacji:

2010-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.82.Fk
65.40.De

Opis:

The lattice parameter for polycrystalline diamond is determined as a function of temperature in the 4-300 K temperature range. In the range studied, the lattice parameter, expressed in angstrom units, of the studied sample increases according to the equation a = 3.566810(12) + 6.37(41) × $10^{-14} T^{4}$ (approximately, from 3.5668 to 3.5673 Å). This increase is larger than that earlier reported for pure single crystals. The observed dependence and the resulting thermal expansion coefficient are discussed on the basis of literature data reported for diamond single crystals and polycrystals.

Źródło:

Acta Physica Polonica A; 2010, 117, 2; 323-327
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

Tunneling in Double-Barrier Heterostructures - Comparison of Time-Dependent and Stationary Approach

Autorzy:

Bała, P.
Ryszewski, R.
Bała, W.

Powiązania:

https://bibliotekanauki.pl/articles/1929716.pdf

Data publikacji:

1993-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.40.Gk
03.65.-w

Opis:

The tunneling probability through a double-barrier ZnSe/ZnTe structure is calculated using both wave-packet time dependent quantum mechanics and stationary planar-wave approximation. The obtained I-V characteristics are compared and very good consistence in resonant peaks width and position is observed. The absolute value of tunneling probability obtained in time-dependent and stationary approach is also similar.

Źródło:

Acta Physica Polonica A; 1993, 84, 4; 685-688
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

AC Susceptibility Measurements in the Investigation of Aggregation in Magnetic Fluids

Autorzy:

Fannin, P. C.
Charles, S. W.

Powiązania:

https://bibliotekanauki.pl/articles/2013237.pdf

Data publikacji:

2000-03

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Tt
76.20.+q

Opis:

Measurements of the complex, frequency dependent susceptibility, χ(ω)=χ '(ω)-iχ''(ω) of two water based magnetic fluids, over the frequency range 10 Hz to 1 MHz are reported. Plots of the susceptibility components against log[f(Hz)] are found to have approximate Debye-type profiles with the presence of Brownian relaxation being indicated by the frequency, f$\text{}_{max}$, of the maximum of the loss-peaks in the χ''(ω) profiles. Corresponding calculations of particle hydrodynamic radius indicate the presence of aggregation. Frohlich, normal and lognormal distribution functions are used to obtain an estimate of the aggregate size distribution in the samples.

Źródło:

Acta Physica Polonica A; 2000, 97, 3; 591-594
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Non-Fermi Liquid Behavior of Correlated Fermions in Applied Field

Autorzy:

Korbel, P.
Spałek, J.
Wójcik, W.

Powiązania:

https://bibliotekanauki.pl/articles/1964622.pdf

Data publikacji:

1997-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.27.+a
71.30.+h
71.10.Fd

Opis:

We have determined an instability of the Fermi-liquid state of almost localized fermions in an applied magnetic field. It is proposed that a transition to a strongly correlated fermions (statistical-spin-liquid) state takes place at that point. The resultant magnetization curve and the field dependence of the specific heat are calculated and compared with those for CeRu$\text{}_{2}$Si$\text{}_{2}$.

Źródło:

Acta Physica Polonica A; 1997, 92, 2; 323-326
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 31.

Tytuł:

Spin Polarons in Weakly Doped Antiferromagnets: Experimental Evidence Obtained for Cuprates

Autorzy:

Wróbel, P.
Suleja, W.
Eder, R.

Powiązania:

https://bibliotekanauki.pl/articles/1812270.pdf

Data publikacji:

2008-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.27.+a
71.10.Fd
74.72.-h

Opis:

The mechanism of spin polaron formation in moderately doped cuprates is discussed. These objects represent holes embedded into heavy clouds formed by spin fluctuations. Wave functions of spin polarons are spatially confined due to the increase in the exchange energy which is induced by hole motion giving rise to the creation of spin fluctuations. These wave functions are eigenstates of an "unperturbed" Hamiltonian which is defined by processes responsible for the tendency toward confinement. The eigenstates transform according to different irreducible representations of the point group reflecting the symmetry of the problem. Thus, the spin polarons being local wave functions resemble orbital states. The spectrum of optical conductivity in the mid-infrared range is determined by transitions between s-wave and p-wave spin polarons. The hybridization between different spin polarons which is induced by some high order processes gives rise to the formation of energy bands. The pronounced transfer of the spectral weight between different bands is induced by the coupling between spin fluctuations created by the hopping hole and local quantum fluctuations in the empty antiferromagnetic background from which an electron has been rejected, for example during the photoemission process. The form of the energy dispersion for spin polarons gives rise to the formation of a small Fermi surface at the low hole-doping range. These three above mentioned phenomena were observed in cuprates which seems to confirm the spin polaron scenario. The discussion of related experiments is the additional objective of this paper.

Źródło:

Acta Physica Polonica A; 2008, 114, 1; 51-58
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Transport of Photoexcited Electron-Hole Plasma in GaN/AlGaN Quantum Well

Autorzy:

Korona, K.
Caban, P.
Strupiński, W.

Powiązania:

https://bibliotekanauki.pl/articles/1791352.pdf

Data publikacji:

2009-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.61.Ey
72.40.+w

Opis:

We report spatially resolved photocurrent measurements showing transport of excitation on long distances in plane of a 6 nm GaN/$Al_{0.1}Ga_{0.9}N$ quantum well. The strong field present in nitrides (due to large spontaneous and piezoelectric polarizations) leads to lower recombination rates of electrons and holes, so in the case of electron-hole pairs excited by light, relatively long-lived electron-hole plasma could be generated. In the case of the investigated quantum well, lifetime of few μs was expected. The thermal measurements showed that barriers were low enough, so all excited carriers could reach the electrode (thermal activation energy of 0.11 eV was found). The diffusion length for unbiased structure was about 40 μm. It was observed that the charge transport could be clearly accelerated by bias. In the biased quantum well, the transport range was of the order of 100 μm under both positive and negative bias. The reported effect of long transport range is very important for electronic devices made on the GaN/AlGaN structures.

Źródło:

Acta Physica Polonica A; 2009, 116, 5; 927-929
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

Analysis of the Experimental Data from MOS Structures in the Case of Large Noise-to-Signal Ratio

Autorzy:

Borowicz, L.
Borowicz, P.
Rzodkiewicz, W.

Powiązania:

https://bibliotekanauki.pl/articles/1807595.pdf

Data publikacji:

2009-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.55.Ye
85.30.Tv
77.55.-g
42.60.Mi

Opis:

The signal coming from $SiO_{2}$ layer of MOS structure have large noise-to-signal ratio. This has two reasons - first: the dielectric layers have small Raman efficiency, second: the thickness of the dielectric layers are of the order of 10 nm, so the volume of the material irradiated with laser light is small. At the other side spectroscopic and optical data carry the information about important properties of the structure like mechanical stress. Distribution of mechanical stress introduce an important contribution to the electric properties of the electronic systems based on the MOS structures. Therefore, it is important to "distillate" the optical data from the noise. In this contribution the authors discuss some methods of denoising of the Raman signal. The discussed methods compare treatments like wavelet analysis or convolution. The work is illustrated with some examples of the extraction of the data coming from thin layers. The examples of application of the optical data in the description of the properties of the studied structures are presented.

Źródło:

Acta Physica Polonica A; 2009, 116, S; S-26-S-29
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 34.

Tytuł:

Pressure Dependence of Exciton Binding Energy in GaN/Al$\text{}_{x}$Ga$\text{}_{1 - x}$N Quantum Wells

Autorzy:

Bardyszewski, W.
Łepkowski, S. P.
Teisseyre, H.

Powiązania:

https://bibliotekanauki.pl/articles/2048086.pdf

Data publikacji:

2011-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.40.Fy
78.20.Bh
78.30.Fs

Opis:

We present a theoretical study of excitons in GaN/Al$\text{}_{x}$Ga$\text{}_{1 - x}$N wurtzite (0001) quantum wells subjected to hydrostatic pressure. Our results show that the combined effect of pressure induced changes in band structure and piezoelectric field leads to reduction of the exciton binding energy. This subtle effect is described quite accurately by our multiband model of excitons in quantum wells.

Źródło:

Acta Physica Polonica A; 2011, 119, 5; 663-665
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Comparative Studies of Vibronic Transitions in One- and Two-Photon Spectra of Gd$\text{}^{3+}$ in Cs$\text{}_{2}$NaGdCl$\text{}_{6}$

Autorzy:

Dereń, P. J.
Stręk, W.
Hanuza, J.

Powiązania:

https://bibliotekanauki.pl/articles/1945614.pdf

Data publikacji:

1996-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.55.Hx

Opis:

Vibronic spectra of Gd$\text{}^{3+}$ in Cs$\text{}_{2}$NaGdCl$\text{}_{6}$ were measured under one- and two-photon excitations. Following the vibrational analysis of the Cs$\text{}_{2}$NaGdCl$\text{}_{6}$ crystal an assignment of vibronic transitions was proposed. It was found that the vibronic transitions in one- and two-photon spectra are combined with the odd parity modes.

Źródło:

Acta Physica Polonica A; 1996, 90, 2; 295-300
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 36.

Tytuł:

Time Dependent Tunneling in Double-Barrier ZnSe/ZnTe Structures

Autorzy:

Bała, P.
Kwiatkowski, J. S.
Bała, W.

Powiązania:

https://bibliotekanauki.pl/articles/1921560.pdf

Data publikacji:

1992-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

03.65.-w
73.40.Gk
73.60.Fw

Opis:

The wave-packet time dependent quantum mechanics is used to calculate tunneling probability through a double-barrier ZnSe/ZnTe structure. The time dependent I-V characteristics are obtained for several structures. The resonant peaks are observed and their changes with the barrier parameters are monitored.

Źródło:

Acta Physica Polonica A; 1992, 82, 4; 649-652
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 37.

Tytuł:

Prototype Silicon Position-Sensitive Detector Working with Bragg-Brentano Powder Diffractometer

Autorzy:

Zięba, A.
Dąbrowski, W.
Gryboś, P.
Powroźnik, W.
Stobiecki, T.
Świentek, K.
Słowik, J.
Wiącek, P.

Powiązania:

https://bibliotekanauki.pl/articles/2030562.pdf

Data publikacji:

2002-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

07.85.-m
29.40.Wk

Opis:

A prototype 64-channel detector module, comprising a silicon strip detector with strip pitch of 100μm and 64-channel ASIC RX64, was tested with the X-Pert Philips MPD diffractometer. Basic parameters of the detector module, energy resolution, and detection efficiency, were evaluated as a function of the counting rate. Energy resolution of 1.1 keV FWHM for photon rate up to 1×10$\text{}^{7}$ photon/s per 1 cm of the active width of the detector was demonstrated. The prototype detector, when applied in a diffractometer utilizing Bragg-Brentano focusing principle, allows to increase the counting rate by about 2 orders of magnitude with respect to a single counter. Exemplary diffraction patterns of polycrystalline samples of Si and SiO$\text{}_{2}$ (quartz peak cluster) are presented.

Źródło:

Acta Physica Polonica A; 2002, 101, 5; 629-634
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Interacting Electrons and Holes in Quasi-2D Quantum Dots in Strong Magnetic Fields

Autorzy:

Hawrylak, P.
Sheng, W.
Cheng, S.-J.

Powiązania:

https://bibliotekanauki.pl/articles/2038355.pdf

Data publikacji:

2004-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.21.-b
83.35.-p
73.21.La
71.35.Ji
78.67.Hc

Opis:

Theory of optical properties of interacting electrons and holes in quasi-2D quantum dots in strong magnetic fields is discussed. In two dimensions and the lowest Landau level, hidden symmetries control the interaction of the interacting system with light. By confining electrons and holes into quantum dots hidden symmetries can be removed and the excitation spectrum of electrons and excitons can be observed. We discuss a theory electronic and of excitonic quantum Hall droplets at a filling factorν=2. For an excitonic quantum Hall droplet the characteristic emission spectra are predicted to be related to the total spin of electron and hole configurations. For the electronic droplet the excitation spectrum of the droplet can be mapped out by measuring the emission for increasing number of electrons.

Źródło:

Acta Physica Polonica A; 2004, 106, 3; 403-412
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Electron Paramagnetic Resonance Study of Se-Doped AlSb: Evidence for Negative-U of the DX Center

Autorzy:

Stallinga, P.
Walukiewicz, W.
Weber, E.R.
Becla, P.
Lagowski, J.

Powiązania:

https://bibliotekanauki.pl/articles/1943839.pdf

Data publikacji:

1995-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.55.Eq
76.30.Da

Opis:

A metastable electron paramagnetic resonance signal is observed in Se doped AlSb. After illumination a strong, persistent electron paramagnetic resonance signal with an isotropic g-factor of 1.949 is observed. The absence of any electron paramagnetic resonance when cooled in the dark is direct evidence for the negative-U model. The electron paramagnetic resonance arises from the effective-mass state of the defect, which is not filled at thermal equilibrium. An analysis of the lineshape reveals that the linewidth is determined by hyperfine interactions. The extend of the wave function is found to be comparable to the prediction for the effective-mass state.

Źródło:

Acta Physica Polonica A; 1995, 88, 5; 1043-1047
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

The C$\text{}^{1}$Σ$\text{}^{+}$ State of KLi Studied by Polarisation Labelling Spectroscopy Technique

Autorzy:

Grochola, A.
Kowalczyk, P.
Jastrzębski, W.
Crozet, P.
Ross, A. J.

Powiązania:

https://bibliotekanauki.pl/articles/2035622.pdf

Data publikacji:

2002-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

33.20.Kf
33.15.-e
34.20.Cf

Opis:

The polarisation labelling spectroscopy method is applied to study the C$\text{}^{1}$Σ$\text{}^{+}$← X$\text{}^{1}$ Σ$\text{}^{+}$ band system of the KLi molecule. Rotationally resolved polarisation spectra are observed in the spectral range of 17150-20350 cm$\text{}^{-1}$. A set of Dunham coefficients describes the C$\text{}^{1}$Σ$\text{}^{+}$ state to 95% of its potential well depth, and the potential curve is constructed by the Rydberg-Klein-Rees procedure. The molecular parameters deduced from this work are compared with theoretical calculations.

Źródło:

Acta Physica Polonica A; 2002, 102, 6; 729-738
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Magnetron Sputtered SnO$\text{}_{x}$ Films on Tin Probed by Slow Positron Implantation Spectroscopy

Autorzy:

Nancheva, N.
Docheva, P.
Anwand, W.
Brauer, G.
Coleman, P. G.

Powiązania:

https://bibliotekanauki.pl/articles/2008107.pdf

Data publikacji:

1999-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.70.-g

Opis:

SnO$\text{}_{x}$ films grown on tin substrates via d.c. magnetron sputtering at different bias were studied by slow positron implantation spectroscopy. The change of substrate bias from -40 V to -140 V and its influence on the films is shown and discussed.

Źródło:

Acta Physica Polonica A; 1999, 95, 4; 623-626
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

Resonant Tunnelling Studies of Chaos in Quantised Systems

Autorzy:

Eaves, L.
Fromhold, T. M.
Wilkinson, P. P.
Sheard, F. W.

Powiązania:

https://bibliotekanauki.pl/articles/1967958.pdf

Data publikacji:

1997-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

72.20.My
73.40.Gk
85.30.Mn
05.45.+b

Opis:

This paper gives a brief introductory overview of quantum chaology, with particular reference to recent experimental work involving the use of semiconductor heterostructures. In the presence of a tilted magnetic field, a double-barrier resonant-tunnelling device incorporating a quantum well produces a chaotic stadium for electron motion. The basic properties of this system are described. It is shown how resonant magnetotunnelling spectroscopy provides firm experimental evidence for the effect of scarred wave functions on a physically-measurable property, in this case the measured current-voltage characteristics of the device. The paper concludes with some speculations concerning for the development of this field.

Źródło:

Acta Physica Polonica A; 1997, 92, 4; 609-619
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

High Field Magnetotransport of the Pressure Induced Organic Superconductor (BEDT-TTF)$\text{}_{3}$Cl$\text{}_{2}$2H$\text{}_{2}$O

Autorzy:

Lubczyński, W.
Caulfield, J.
Singleton, J.
Hayes, W.
Kurmoo, M.
Day, P.

Powiązania:

https://bibliotekanauki.pl/articles/1933345.pdf

Data publikacji:

1995-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

72.15.Nj

Opis:

The magnetotransport of single crystals of (BEDT-TTF)$\text{}_{3}$Cl$\text{}_{2}$2H$\text{}_{2}$0 was studied in the Pressure range 10÷20 kbar at continuous magnetic fields up to 15 T and at temperatures down to 700 mK. Above 12.5 kbar a single series of Shubnikov-de Haas oscillations is observed, corresponding to about 0.5-1% of the cross-section of the first Brillouin zone. A superconducting state with the highest transition temperature close to 3 K is stabilised between 10.2 kbar and 13.5 kbar.

Źródło:

Acta Physica Polonica A; 1995, 87, 4-5; 777-779
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Coupling of Quantum Dots with Quantum Wells in a System Based on (Cd,Zn,Mg)Te

Autorzy:

Połczyńska, K.
Janik, E.
Kossacki, P.
Pacuski, W.

Powiązania:

https://bibliotekanauki.pl/articles/1033157.pdf

Data publikacji:

2017-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.55.Et
78.67.Hc
73.21.La
78.67.-n

Opis:

Coupled low dimensional structures have potential applications in quantum computing and spintronics. Using molecular beam epitaxy we fabricated three kinds of systems of coupled quantum wells and quantum dots with different energy order: wells at higher energy than dots, resonant structures, and dots at higher energy than wells. By analysis of photoluminescence and reflectivity spectra, we conclude that there is a possibility of effective carrier tunneling between structures, which opens possibility of subsequent testing of spin transfer efficiency.

Źródło:

Acta Physica Polonica A; 2017, 132, 2; 369-371
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

Estimate of the Crystallite Size for Nanocrystalline AISI 316L Stainless Steel and Armco Iron Processed by Hydrostatic Extrusion Using Variable Energy Positron Beam

Autorzy:

Sarnek, M.
Dryzek, E.
Horodek, P.
Pachla, W.

Powiązania:

https://bibliotekanauki.pl/articles/1033950.pdf

Data publikacji:

2017-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

stainless steel
Armco iron
plastic deformation
hydrostatic extrusion
variable energy positron beam
X-ray diffraction

Opis:

The paper presents the results of research of nanocrystalline AISI 316L type stainless steel and nanocrystalline Armco pure iron processed by severe plastic deformation using hydrostatic extrusion method. Surface and subsurface of the steel samples extruded at different pressure were investigated using variable energy positron beam. It enabled us to determine the positron diffusion length and compare its values with those for annealed AISI 304 stainless steel. Furthermore positron lifetime and microhardness were measured for all the samples and X-ray diffraction was used to estimate the crystallite size.

Źródło:

Acta Physica Polonica A; 2017, 132, 5; 1598-1601
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Glass forming abilities and crystallization process in amorphous Pr-Fe-Co-Zr-Nb-B alloys of various B content

Autorzy:

Pawlik, K.
Pawlik, P.
Kaszuwara, W.
Wysłocki, J.

Powiązania:

https://bibliotekanauki.pl/articles/1054842.pdf

Data publikacji:

2017-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

64.70.dg
61.05.cp
75.20.En
75.50.Vv

Opis:

The influence of boron contents on the glass forming abilities and magnetic properties of melt-spun ribbon samples produced from Pr₉Fe_{50+x}Co₁₃Zr₁Nb₄B_{23-x} (x=0, 2, 5, 8) alloys, were investigated. For all compositions, the rapidly solidified samples were fully amorphous, which was confirmed by X-ray diffractometry and the Mössbauer spectroscopy. Differential scanning calorimetry and differential thermal analysis studies revealed good glass forming abilities for all investigated specimens and allowed to determine thermal stability parameters of the amorphous phase. For all alloy ribbons, very large supercooled liquid region before crystallization ΔT_x reaching 100 K was measured. The Kissinger plots were constructed to determine the activation energies for crystallization. Annealing of specimens at temperatures ranging from 923 K to 1033 K for 5 min resulted in significant change of the phase constitution. The X-ray diffractometry studies have shown presence of hard magnetic Pr₂(Fe,Co)₁₄B and paramagnetic Pr_{1+x}Fe₄B₄ phases. Furthermore, with the increase of B contents in the alloy composition crystallization of α-Fe phase occurs at wider range of the annealing temperature. Anomaly of both thermal and magnetic properties was observed for the Pr₉Fe₅₂Co₁₃Zr₁Nb₄B₂₁ alloy ribbons.

Źródło:

Acta Physica Polonica A; 2017, 131, 4; 979-981
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

New type of composite gyrotropic metamaterial

Autorzy:

Paśko, W.
Zięba, P.
Tralle, I.
Çoruh, A.

Powiązania:

https://bibliotekanauki.pl/articles/1055044.pdf

Data publikacji:

2017-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.05.Xj
81.05.Zx
78.67.Pt
42.70.-a

Opis:

In this work we examined the possibility of fabricating the metamaterial in a relatively simple way. Our idea was to use the three-component mixture of ingredients, where one of them is responsible for the negative permeability μ(ω) of hypothetical metamaterial, while the other two cause the negative value of effective permittivity ε(ω). In our previous work, we considered Hg_{1-x}Cd_xTe semiconductor compound as one of the ingredients of mixture. As fabrication of the Hg_{1-x}Cd_xTe is related to using mercury which is very poisoning, we tried to exclude this material. In the work we proved by numerical simulations the possibility of substituting mercury cadmium telluride by Pb_{1-x}Sn_xTe. We have shown by computer simulations that by the proper fitting of the parameters, e.g. the radius of nanoparticles, their magnetic moments, the relative concentration of ingredients, etc., it is possible to obtain the metamaterial with negative refraction index in a relatively broad range of temperatures and magnetic fields. The last seems to be very promising in terms of practical applications of metamaterials.

Źródło:

Acta Physica Polonica A; 2017, 132, 1; 121-123
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 48.

Tytuł:

Magnetization Reversal Processes in the Nanocrystalline Fe-Co-Zr-Ti-Pr-B Magnets

Autorzy:

Pawlik, K.
Pawlik, P.
Wysłocki, J.
Kaszuwara, W.

Powiązania:

https://bibliotekanauki.pl/articles/1813515.pdf

Data publikacji:

2008-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Ww
75.50.Kj
71.20.Eh

Opis:

Magnetization reversal processes in the magnets derived from the $Fe_{60}Co_{13}Zr_1Ti_3Pr_9B_{14}$ alloy were investigated. It was shown that the processing technique affects the magnetization reversal processes. For the nanocrystalline ribbon samples pinning of the domain walls arises at low external magnetic fields while nucleation of reversed domains occurs at higher fields. However, the nucleation fields are lower than the pinning fields for the nanocrystalline rod and tube samples produced by suction-casting technique.

Źródło:

Acta Physica Polonica A; 2008, 113, 1; 39-42
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 49.

Tytuł:

Nonlinear Effects with Ultrashort Laser Pulses

Autorzy:

Wasylczyk, P.
Wasilewski, W.
Trippenbach, M.
Radzewicz, C.

Powiązania:

https://bibliotekanauki.pl/articles/2030301.pdf

Data publikacji:

2002-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.65.Jx
42.65.Sf

Opis:

Propagation of an intense femtosecond laser pulse through a transparent nonlinear medium such as dielectric leads to a number of phenomena. In our experiment we observed complex spatial, spectral, and temporal structures appearing in the initially smooth femtosecond laser pulse when the pulse power is comparable to or higher than the critical power for self-focusing. We have also developed a complete, 3-dimensional theoretical model to describe the observed phenomena.

Źródło:

Acta Physica Polonica A; 2002, 101, 1; 89-104
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 50.

Tytuł:

Ground State Properties of Tb$\text{}^{3+}$ Ion in TbNi$\text{}_{10}$Si$\text{}_{2}$

Autorzy:

Stefański, P.
Suski, W.
Wochowski, K.
Mydlarz, T.

Powiązania:

https://bibliotekanauki.pl/articles/1964565.pdf

Data publikacji:

1997-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.30.Gw
75.50.Gg

Opis:

Ground state properties of Tb$\text{}^{3+}$ ion were investigated in the tetragonal ThΜn$\text{}_{12}$-type TbNi$\text{}_{10}$Si$\text{}_{2}$ compound on the basis of temperature dependence of the paramagnetic susceptibility and magnetization measurements. The rare earth temperature dependence of the susceptibility was calculated using the Van Vleck equation. The Γ$\text{}_{t5}^{(1)}$ doublet is suggested to be a ground state separated by 9 K from the first excited singlet Γ$\text{}_{t1}^{(2)}$. The magnetic moment associated with the ground state doublet agrees with saturation magnetization data at 4.2 K. The overall crystal field splitting is estimated to be 105 K.

Źródło:

Acta Physica Polonica A; 1997, 92, 2; 281-284
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 51.

Tytuł:

Longitudinal Strain Induced Birefringence in Highly Birefringent Fiber for Dynamic Compensation of Polarization Mode Dispersion

Autorzy:

Domański, A. W.
Lesiak, P.
Woliński, T. R.

Powiązania:

https://bibliotekanauki.pl/articles/2035697.pdf

Data publikacji:

2003

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.81.Gs
42.81.Pa
42.25.Ja
42.25.Dd

Opis:

The paper addresses a compensation method of polarization mode dispersion based on longitudinal strain applied to a highly birefringent fiber introduced as apart from optical fiber link. As an introduction a short overview of the polarization mode dispersion compensation methods known up-to-now is done. Dependence of polarization mode dispersion on longitudinal strain is discussed. Some results of experiment with birefringence changes due to longitudinal strain in the bow-tie highly birefringent fiber necessary for dynamic polarization mode dispersion are presented.

Źródło:

Acta Physica Polonica A; 2003, 103, 2-3; 221-227
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 52.

Tytuł:

Superconductivity and Magnetism in Nd$\text{}_{0.5}$Sr$\text{}_{0.5}$MnO$\text{}_{3}$/YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7}$ Superlattices

Autorzy:

Tsarou, A.
Paszkowicz, W.
Minikayev, R.
Dłużewski, P.
Sawicki, M.
Przysłupski, P.

Powiązania:

https://bibliotekanauki.pl/articles/2047250.pdf

Data publikacji:

2007-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

74.25.Ha
74.78.Fk
75.70.Cn

Opis:

We report the synthesis and characterization of Nd$\text{}_{0.5}$Sr$\text{}_{0.5}$MnO$\text{}_{3}$/YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7}$ superlattices. X-ray diffraction studies show that the superlattices are [001] oriented. We observe that the magnetic ground state of Nd$\text{}_{0.5}$Sr$\text{}_{0.5}$MnO$\text{}_{3}$ system in a multilayered structure is strongly dependent on the substrate.

Źródło:

Acta Physica Polonica A; 2007, 111, 1; 179-183
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 53.

Tytuł:

Influence of Impurity Charge Correlation on Free-Carrier Absorption

Autorzy:

Szuszkiewicz, W.
Sobkowicz, P.
Witkowska, B.
Bardyszewski, W.
Julien, C.
Balkanski, M.

Powiązania:

https://bibliotekanauki.pl/articles/1929654.pdf

Data publikacji:

1993-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.45.Gm
72.30.+q
75.50.Pp

Opis:

Impurity-mediated free-carrier absorption was analyzed theoretically taking into account the possible spatial impurity correlations. The effect of correlations was included via the structure factor S(q) obtained from finite temperature Monte Carlo simulations of ordering in the impurity system. From the comparison of the experimental data with the results of calculations it is demonstrated that the ordering of charged centers exists for HgSe:Fe in a wide temperature range.

Źródło:

Acta Physica Polonica A; 1993, 84, 3; 559-562
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 54.

Tytuł:

Free Radicals in K and Rb Admixtured Fullerene C$\text{}_{60}$

Autorzy:

Stankowski, J.
Kempiński, W.
Byszewski, P.
Trybuła, Z.

Powiązania:

https://bibliotekanauki.pl/articles/1929831.pdf

Data publikacji:

1993-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

76.30.Rn
74.70.Wz

Opis:

Molecules of C$\text{}_{60}$ form Van der Waals type crystals. The observations reported here concern EPR investigations of such C$\text{}_{60}$ samples with only a slight amount of Rb or K. Detected defects are (C$\text{}_{60}$)$\text{}^{+}$ or (C$\text{}_{60}$)$\text{}^{y-}$ ion-radicals. A hole (h) or trapped electron (t) are localized on one fullerene ball. In the case of potassium fullerites C$\text{}_{60}$:K the line shape of EPR signal was of the Dysonian form which is characteristic of conducting electrons in metal. The EPR lines of holes (C$\text{}_{60}$)$\text{}^{+}$ are characterized by g$\text{}_{h}$ ≥ g$\text{}_{0}$ whereas for electrons g$\text{}_{t}$ is below the value g$\text{}_{0}$ = 2.0023 characteristic of a free electron (g$\text{}_{t}$ ≤ g$\text{}_{0}$). The EPR linewidth 2ΔB$\text{}_{1s}^{h}$ of the (C$\text{}_{60}$)$\text{}^{+}$ weakly increased with decreasing temperature whereas the EPR linewidth attributed to the electron 2ΔB$\text{}^{t}$$\text{}_{1s}$ significantly decreases with decreasing temperature. The C$\text{}_{60}$:K sample reached superconducting phase below T$\text{}_{c}$ = 11 K which is significantly less than T$\text{}_{c}$ = 16.5 K observed for K$\text{}_{x}$C$\text{}_{60}$ where 2 ≤ x ≤ 4.

Źródło:

Acta Physica Polonica A; 1993, 84, 6; 1117-1123
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 55.

Tytuł:

Polypropylene Films Studied with Variable Positron Beams

Autorzy:

Dębowska, M.
Coleman, P. G.
Gidley, D. W.

Powiązania:

https://bibliotekanauki.pl/articles/2007958.pdf

Data publikacji:

1999-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

36.10.Dr
61.41.+e
71.60.+z
78.70.Bj

Opis:

Doppler broadening and positron lifetime spectra have been measured for polypropylene films of constant thickness (≈ 50 μm) and different morphology that crystallized from melt at temperature 0, 100, and 120°C. The S -parameter vs. energy curves do not change in a systematic way with crystallinity of samples. It is supposed that decrease in the fractional free volume for samples of greater crystallinity is not seen in S-values because of their increase resulting from annihilation in defects present both in the crystalline regions and on the lamellae surfaces. Intensities of the components in the positron lifetime spectra: I$\text{}_{2}$ (τ$\text{}_{2}$=1.3 ns) and I$\text{}_{3}$ (τ$\text{}_{3}$≈ 2.3÷2.8 ns) show changes with crystallinity of samples. The evident trend is observed for the longer-lived τ$\text{}_{3}$-component intensity to decrease with crystallinity while the reverse is true for the shorter, fixed τ$\text{}_{2}$-component. The decrease in the intensity of the longer-lived component can result from reduction of the fractional free volume.

Źródło:

Acta Physica Polonica A; 1999, 95, 4; 496-504
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 56.

Tytuł:

Characterization of Sn Films on Silicon by Slow Positron Implantation Spectroscopy

Autorzy:

Nancheva, N.
Docheva, P.
Anwand, W.
Brauer, G.

Powiązania:

https://bibliotekanauki.pl/articles/2025741.pdf

Data publikacji:

2001

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

68.75.+x
78.70.

Opis:

Sn films grown on silicon substrate by d.c. magnetron sputtering have been investigated by slow positron implantation spectroscopy. As the substrate bias is one of the most important factors affecting the structure of a sputtered film, films grown at various substrate bias (+80 V, 0 V, -80 V) are compared and their properties are discussed.

Źródło:

Acta Physica Polonica A; 2001, 99, 3-4; 435-440
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 57.

Tytuł:

An Improvement of Magnetic Flux Linkage in Electrical Generator using the novel Permanent Magnet Arrangement

Autorzy:

Sriwannarat, W.
Khunkitti, P.
Janon, A.
Siritaratiwat, A.

Powiązania:

https://bibliotekanauki.pl/articles/1030384.pdf

Data publikacji:

2018-03

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

03.50.De
07.55.Db
75.50.Ww
83.60.Np
84.30.Ng
85.70.Ay

Opis:

The partitioned stator permanent magnet generator (PS-PMG) has been extensively used as electrical generator due mainly to their high flux linkage, high electromotive force EMF) and high efficiency, especially the PM arrangement of the PS-PMG is an important factor to improve the performance of the generator. Therefore, we propose the novel permanent magnet PM) arrangement of the PS-PMG by using the dual rotor with coaxial core structure in order to improve the flux linkage and the EMF of PS-PMG. The PM position of stators of the conventional PS-PMG was rearranged, then the electrical characteristic of the proposed structure was characterized through the simulations based on finite element method. It was found that the flux linkage produced by the proposed structure is 37.06% higher than that of the conventional PS-PMG existed in the literatures because the area for induced flux linkage is significantly increased. This flux linkage enhancement further causes an increment of EMF about 34.95% compared to that of the conventional PS-PMG under the same condition. Especially, the EMF produced by the proposed structure is classified in the high-value range regarding the PM generator. Then, the PS-PMG using novel permanent magnet arrangement could be another remarkable choice for the electrical generator application

Źródło:

Acta Physica Polonica A; 2018, 133, 3; 642-644
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 58.

Tytuł:

Effect of Fe substitution on structural and magnetic properties of NiCr₂O₄

Autorzy:

Mohanty, P.
Prinsloo, A.
Sheppard, C.
Roos, W.

Powiązania:

https://bibliotekanauki.pl/articles/1048307.pdf

Data publikacji:

2018-03

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Gg
75.60.-d

Opis:

At room temperature, the normal oxide spinel NiCr₂O₄ is tetragonally distorted and crystallizes in the I4₁/amd space group due to cooperative Jahn-Teller ordering driven by the orbital degeneracy of tetrahedral Ni²⁺. The ferrimagnetic Curie temperature (T_{C}) for NiCr₂O₄ is 74 K. The magnetic moments of NiCr₂O₄ are composed of a ferrimagnetic (longitudinal) and an antiferromagnetic (transverse) component. Exchange interaction between the magnetic cations influences the overall magnetic properties of the compound. Present work focuses on the modification of structural and magnetic properties upon substituting Fe at Cr site in NiCr₂O₄ with the motivation of changing the magnetic exchange interaction. In order to do so, single phase Ni(Cr_{0.5}Fe_{0.5})₂O₄ samples were prepared by co-precipitation techniques, while controlling the pH of precipitation. Upon Fe substitution, crystal structure was not affected much contrary to the earlier reports. In order to determine the oxidation state of each elements X-ray photoelectron spectroscopy (XPS) was performed. T_{C} was found to increase dramatically above 300 K, confirmed both from temperature and field dependent dc-magnetization studies.

Źródło:

Acta Physica Polonica A; 2018, 133, 3; 574-577
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 59.

Tytuł:

The Electronic and Magnetic Properties οf $UNiAs_2$ Antiferromagnet

Autorzy:

Werwiński, M.
Szajek, A.
Leśniak, P.
Malinowski, W.

Powiązania:

https://bibliotekanauki.pl/articles/1537251.pdf

Data publikacji:

2010-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.20.-j

Opis:

$UNiAs_2$ band structure has been calculated based on two full-potential methods: full potential linearized augmented plane wave implemented in WIEN2k code and full-potential local-orbital minimum-basis in FPLO code. Starting from the local (spin) density approximation (L(S)DA) we verified either the orbital polarization correction or the LSDA+U approach with the Coulomb repulsion energies U of 0-4 eV for the uranium 5f electrons. Calculated magnetic moments confirm antiferromagnetic ground state and collinear magnetic sequence. The best agreement with experimental results has been achieved by applying orbital polarization corrections, the magnetic moment on uranium amounts to 1.76 $μ_{B}$ per U atom.

Źródło:

Acta Physica Polonica A; 2010, 118, 2; 413-416
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 60.

Tytuł:

Charge Orderings and Phase Separations in Itinerant Fermion Systems at Half Filling

Autorzy:

Czart, W.
Grzybowski, P.
Nogala, M.
Robaszkiewicz, S.

Powiązania:

https://bibliotekanauki.pl/articles/1426750.pdf

Data publikacji:

2012-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.10.Fd
71.30.+h
71.45.Lr
64.75.Gh

Opis:

We analyse the ground state phase diagrams of the charge orderings in narrow band materials using two effective models: (1) the spinless fermion model (t - W) with repulsive intersite interaction ($W_{ij}$ > 0) and (2) the molecular crystal model with the coupling of electrons to intramolecular (crystal field) vibrations. We present results for the case of half filled bands for d = 2 square lattice. The calculations are performed within the (broken symmetry) Hartree-Fock approximation. The study takes into consideration the effects of frustrating next-nearest-neighbour hopping $(t_2)$ on the charge ordered states in these systems. We focus on the two cases: (i) homogeneous phases and phase separations involving checkerboard charge ordering with the nesting vector Q= (π,π) only and (ii) homogeneous phases and phase separations involving two types of charge ordering: (a) checkerboard charge ordering with the nesting vector Q = (π,π), and (b) collinear (CL) charge ordering with Q = (0,π) or Q = (π,0).

Źródło:

Acta Physica Polonica A; 2012, 121, 5-6; 1042-1044
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 61.

Tytuł:

Effects of Frustrating Hopping on Charge Ordered States in Itinerant Fermion Systems for Arbitrary Concentration in 2D Lattice

Autorzy:

Czart, W.
Grzybowski, P.
Nogala, M.
Robaszkiewicz, S.

Powiązania:

https://bibliotekanauki.pl/articles/1431325.pdf

Data publikacji:

2012-04

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.10.Fd
71.30.+h
71.45.Lr
64.75.Gh

Opis:

There is ongoing, intense, research in the field of electron charge orderings (CO) and charge density waves phenomena, due to experimental discovery of such phases in numerous important compounds. The aim of this work is to extend recent advances in the field by studying two simple effective paradigmatic models used to describe CO in narrow band materials i.e. (i) a model of correlated electrons: the so-called t-W model of spinless fermions with repulsive interaction W and (ii) the molecular crystal model with the coupling of electrons to intramolecular (crystal field) vibrations in the static limit. The finite temperature phase diagrams are evaluated at arbitrary carriers concentration for several representative cases. Our calculations are performed within the (broken symmetry) HFA for d=2 square lattice and arbitrary carriers concentration. In this contribution we focus on the effects of next-nearest-neighbor hopping on the CO states in these systems and the problem of phase separations involving checkerboard CO with the nesting vector Q=(π,π). The results we show here are an extension of our previous work on the subject.

Źródło:

Acta Physica Polonica A; 2012, 121, 4; 828-831
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 62.

Tytuł:

EPR Evidence for Thermally Excited Triplet States in Exinite, Vitrinite and Inertinite Separated from Bituminous Coal

Autorzy:

Słowik, G. P.
Wojtowicz, W.
Więckowski, A. B.

Powiązania:

https://bibliotekanauki.pl/articles/2043436.pdf

Data publikacji:

2005-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.66.Hq
76.30.Rn
87.64.Hd

Opis:

In this work we have made an electron spin resonance (EPR) study of macerals obtained from the lithotype clarain separated from Polish medium-rank coal (85.6 wt.% C). For three macerals:~exinite, vitrinite, and inertinite, the temperature dependence of intensity of EPR spectra in the temperature range of 100-373 K was investigated. The experimentally obtained EPR spectra of macerals were fitted by curves of the derivatives of the Gaussian and Lorentzian functions. The best fitting was obtained, when the experimental EPR spectra were assumed to be a superposition of three lines, for exinite and vitrinite - a broad Gaussian (G), a broad Lorentzian (L1) and a narrow Lorentzian (L3) line, but for inertinite of two lines - a narrow Lorentzian (L2) and a narrow Lorentzian (L3) line. The computer-assisted fitting has shown that each individual component line has similar values of resonance field, but different linewidths and amplitudes. The temperature dependence of line intensity I of the broad Gaussian (G) and narrow Lorentzian (L2 and L3) lines fulfils the Curie law in the form I=C/T or IT=C, whereas the broad Lorentzian (L1) line does not fulfil the Curie law. In the last case the temperature dependence of the Lorentzian (L1) component was fitted by the relation I=C/T+B/[T(3+exp(J/kT))] or IT=C+B/[3+exp(J/kT))], valid for thermally excited triplet states (S=1). For exinite and vitrinite the curves presenting the temperature dependence of the product IT versus temperature T were resolved into two curves, one for paramagnetic centres in the doublet state (S=1/2), and the other for paramagnetic centres in the thermally excited triplet state (S=1).

Źródło:

Acta Physica Polonica A; 2005, 108, 1; 171-176
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 63.

Tytuł:

Magnetization Reversal Processes in Pr-Fe-B-type Nanocrystalline Magnets

Autorzy:

Pawlik, K.
Pawlik, P.
Kaszuwara, W.
Wysłocki, J.

Powiązania:

https://bibliotekanauki.pl/articles/1368000.pdf

Data publikacji:

2014-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.50.Vv
75.60.Ej
75.50.Bb
75.50.Tt
75.50.Ww

Opis:

The magnetization reversal processes in magnets derived from rapidly solidified $Pr_{9}Fe_{52}Co_{13}Zr_{1}Nb_{4}B_{21}$ alloy samples were studied by analysis of minor hysteresis loops and recoil curves. The studies were carried out on suction-cast 1 mm diameter rod, 1 mm thick plate, 3 mm outer diameter (o.d.) tube and melt-spun ribbon samples subjected to annealing at 983 K for 5 min. The X-ray diffraction analysis has shown multiphase constitution of the samples. Structural and magnetic studies indicated that the initial state of microstructure and phase composition affects the magnetization reversal processes in annealed samples due to a variation of microstructure in samples of various shapes. Magnetic studies allowed estimation of the mean values of nucleation and pinning fields that control the magnetization reversal processes.

Źródło:

Acta Physica Polonica A; 2014, 126, 1; 186-187
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 64.

Tytuł:

Angular Distributions of Secondary Electrons Emitted from the Polycrystalline Silver

Autorzy:

Doliński, W.
Palczyński, J.
Mazur, P.
Gieniec, L.

Powiązania:

https://bibliotekanauki.pl/articles/1892474.pdf

Data publikacji:

1992-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

79.20.Hx
79.20.Fv
34.80.Bm

Opis:

The angular distributions of secondary electrons (including Auger electrons) of different energies emitted from polycrystalline silver bombarded with primary electrons (E$\text{}_{p}$ = 1000 and 2500 eV) were measured with a RFA analyzer equipped with an additional collector (acceptance angle ≈ 4°). Additionally, the angular distributions of primary electrons of different energies elastically backscattered from the same sample were also investigated by means of a specially constructed rotable RFA analyzer equipped with a channeltron. The results obtained show the cosine distribution of secondary and Auger electrons emitted as shown previously in the literature. The angular distributions of electrons backscattered elastically depend on electron energy and are in good agreement with theoretical calculations (Monte Carlo simulation of primary electrons trajectories in solids) proposed by Jabłoński.

Źródło:

Acta Physica Polonica A; 1992, 81, 2; 211-222
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 65.

Tytuł:

Magnetic Properties of the $U_5Ge_4$ Compound Based on Ab initio Calculations

Autorzy:

Szajek, A.
Werwiński, M.
Malinowski, W.
Leśniak, P.

Powiązania:

https://bibliotekanauki.pl/articles/1810502.pdf

Data publikacji:

2009-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.20.-b
75.25.+z

Opis:

$U_5Ge_4$ crystallizes in a hexagonal $Ti_5Ga_4$ type structure with two inequivalent crystallographic sites occupied by uranium atoms. The band structure calculations were performed by the full-potential local-orbital minimum basis band structure code. The calculations showed that on both types of uranium atoms small magnetic moments are formed and their values are equal to 0.08 and 0.15 $μ_{B}$/atom, respectively.

Źródło:

Acta Physica Polonica A; 2009, 115, 1; 251-253
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 66.

Tytuł:

A High-Energy Ball Milling as a Useful Technique for the Synthesis of $CaCu_3Ti_4O_{12}$ Electroceramics

Autorzy:

Dulian, P.
Bąk, W.
Kajtoch, Cz.
Wieczorek-Ciurowa, K.

Powiązania:

https://bibliotekanauki.pl/articles/1375214.pdf

Data publikacji:

2014-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

77.22.Gm
81.05.-t

Opis:

This paper shows that $CaCu_3Ti_4O_{12}$ (CCTO) can be synthesized through the high-energy ball milling of CaO, CuO and $TiO_2$ powders. The dielectric characterization of CCTO obtained mechanochemically as well as, for comparison, by a high-temperature method is presented. Moreover, it is illustrated that zirconium oxide in contrast to a metallic iron generated during milling processes improves the properties of CCTO in terms of ceramic capacitors.

Źródło:

Acta Physica Polonica A; 2014, 126, 4; 931-937
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 67.

Tytuł:

Magnetization Relaxation in CdMnS

Autorzy:

Witowski, A. M.
Kutter, Ch.
Mac, W.
Wyder, P.

Powiązania:

https://bibliotekanauki.pl/articles/1929759.pdf

Data publikacji:

1993-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

76.30.Fc

Opis:

The static magnetization measurements and relaxation of magnetization data for two Cd$\text{}_{1-x}$Mn$\text{}_{x}$S samples with different composition are presented. The magnetization is described by the modified Brillouin function. The magnetization relaxation shows unusual composition dependence. This behavior is explained by cross-relaxation to the unknown fast relaxing centers introduced during growth.

Źródło:

Acta Physica Polonica A; 1993, 84, 4; 798-800
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 68.

Tytuł:

Excited States in Solid Phenothiazine as Studied by Electroabsorption Spectroscopy

Autorzy:

Kalinowski, J.
Stampor, W.
Fattori, V.
Di Marco, P.

Powiązania:

https://bibliotekanauki.pl/articles/1933431.pdf

Data publikacji:

1995-06

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

31.50.+w
31.70.Dk
31.70.Ks
33.55.Be

Opis:

Electric field modulated absorption spectra of vapor deposited layers of phenothiazine, explained in terms of a quadratic Stark effect, indicate modification of intramolecular (Frenkel-type) excitons by charge transfer transitions throughout UVIS absorption spectrum in the range 250-450 nm. The charge transfer character of the excited states appears at energies characteristic of various oxidation products of phenothiazine as identified from a spectroscopic study of photochemical air oxidation, performed on solution and solid film samples of this compound. The charge transfer transitions are ascribed to electron transfer between the molecules of phenothiazine and their oxidized species created in the samples during preparation and handling procedures.

Źródło:

Acta Physica Polonica A; 1995, 87, 6; 953-964
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 69.

Tytuł:

Mechanical Characterisation of Modified Aramid Fibres Used in Dentistry

Autorzy:

Malicka-Soczka, A.
Domka, L.
Gajdus, P.
Hędzelek, W.

Powiązania:

https://bibliotekanauki.pl/articles/1810276.pdf

Data publikacji:

2009-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

62.20.-x
68.37.Hk
61.41.+e

Opis:

Reconstructive phase of medical treatment, especially in dentistry, requires the use of different polymers. A common laboratory method to increase the fracture resistance of acrylic resin dentures is to include high-resistance synthetic fibres in the processing protocol. However, in the case of aramid fibres the problem of ensuring high durability of bonding between the fibre and acrylic resin has not been solved yet. The aim of the study is to evaluate the mechanical properties and microstructure of acrylic resin reinforced with modified aramid fibres used as fillers or as fibres treated with epoxy resin. In this study mechanical strength of 10 samples of aramid fibres Kevlar (DuPont) and 10 samples of acrylic resin ProBase (Ivoclar) was determined. The controls were unreinforced samples. The three point loading tests were carried out on a universal testing machine Hounsfield. The structures of the fillers and composites were characterised by the scanning electron microscopy. The results are presented graphically in diagrams and table.

Źródło:

Acta Physica Polonica A; 2009, 115, 2; 599-601
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 70.

Tytuł:

Transition Metal Impurities and Electronic Structure of ZnSe-Based Isovalent Semiconductor Alloys

Autorzy:

Surkova, T. P.
Giriat, W.
Godlewski, M.
Permogorov, S.

Powiązania:

https://bibliotekanauki.pl/articles/1968432.pdf

Data publikacji:

1997-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.20.Wc
71.55.Gs

Opis:

Energy level positions of the nickel 2+/1+ and cobalt 2+/3+ charge states have been used to estimate band edges for the valence and conduction bands of ZnSe-based alloys with cation (ZnCdSe) and anion (ZnSSe) substitution. Chemical trends in band offsets of heterostructures of Zn- or Mn-based II-VI compounds are analysed. Further on, the change of Ni$\text{}^{2+}$(3d$\text{}^{8}$) and Co$\text{}^{2+}$(3d$\text{}^{7}$) intra-d shell transition bands upon the alloying of host material is discussed.

Źródło:

Acta Physica Polonica A; 1997, 92, 5; 1009-1012
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 71.

Tytuł:

Allocation and Properties of Iron States in Cd$\text{}_{1-x}$Fe$\text{}_{x}$Te in Forbidden Gap Energy Range

Autorzy:

Hołda, A.
Rodzik, A.
Melnikov, A.
Żukowski, P. W.

Powiązania:

https://bibliotekanauki.pl/articles/1872765.pdf

Data publikacji:

1995-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.20.Ci
78.20.Jq
78.60.Hk

Opis:

The use of different experimental methods (reflectivity, absorption, photoconductivity and cathodoluminescence) allowed us to confirm the existence of the deep donor-like state of iron and present allocation and properties of the iron states in Cd$\text{}_{1-y}$Fe$\text{}_{x}$Te (0 ≤ x ≤ 0.05) at 300 K and 77 K in the forbidden gap energy range. It was concluded that the increase in width of the forbidden gap with the change of temperature from 300 K to 77 K leads mainly to the rise of the energy distance between the donor-like iron state $\text{}^{5}$E and the bottom of the conduction band.

Źródło:

Acta Physica Polonica A; 1995, 87, 2; 357-360
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 72.

Tytuł:

Surfactant Effect on Synthesis of Nanocrystalline La$\text{}_{x}$Sr$\text{}_{1-x}$MnO$\text{}_{3}$ by Hydrothermal Method

Autorzy:

Sin, W. L.
Wong, K. H.
Li, P. Li.

Powiązania:

https://bibliotekanauki.pl/articles/2047246.pdf

Data publikacji:

2007-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.47.Lx
82.70.Uv
61.10.Nz

Opis:

Crystalline La$\text{}_{x}$Sr$\text{}_{1-x}$MnO$\text{}_{3}$ was prepared by a hydrothermal route in the presence of surfactant. The cationic surfactant of cetyltrimethylammonium bromide as a template is used to regulate the nucleation and crystal growth. The as-synthesized product was characterized by X-ray diffraction and transmission electron microscopy. Nanosized and uniform rod-like monocrystals of La$\text{}_{x}$Sr$\text{}_{1-x}$MnO$\text{}_{3}$ were obtained. Their magnetic properties were studied using a vibrating sample magnetometer. Our results reveal that the use of surfactant helps to lower the processing temperature and to speed up the formation and crystallization of La$\text{}_{x}$Sr$\text{}_{1-x}$MnO$\text{}_{3}$. The surfactant also provides us an additional means of controlling the nanocrystalline size and maintaining the stoichiometry of the as-prepared nanocrystallites.

Źródło:

Acta Physica Polonica A; 2007, 111, 1; 165-171
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 73.

Tytuł:

Photoluminescence of Co-Doped ZnCdSe and ZnSSe Alloys

Autorzy:

Surkova, T. P.
Born, H.
Thurian, P.
Hoffmann, A.
Busse, W.
Gumlich, H.-E.
Broser, I.
Giriat, W.

Powiązania:

https://bibliotekanauki.pl/articles/1968428.pdf

Data publikacji:

1997-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.55.Gs
78.20.Wc

Opis:

Photoluminescence measurements have been carried out for Zn$\text{}_{1-x}$ Cd$\text{}_{x}$ Se:Co and ZnS$\text{}_{x}$Se$\text{}_{1-x}$:Co mixed crystals. Changes of recombination channels are observed in mixed crystals as compared to the emission of host binary compounds. Character of changes is slightly different for the alloys with cation and anion substitution. Photoluminescence kinetics of the L-line and of two other Co$\text{}^{2+}$ intra-shell emission bands was measured to determine radiative decay rates.

Źródło:

Acta Physica Polonica A; 1997, 92, 5; 1013-1016
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 74.

Tytuł:

The Effect of Annealing Temperature on the Phase Constitution and Magnetic Properties of the Pr₈Dy₁Fe₆₀Co₇Mn₆B₁₄Zr₁Ti₃ Alloy Ribbons

Autorzy:

Przybył, A.
Pawlik, K.
Pawlik, P.
Gębara, P.
Kaszuwara, W.
Wysłocki, J.
Filipecka, K.

Powiązania:

https://bibliotekanauki.pl/articles/1402331.pdf

Data publikacji:

2015-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.20.En
91.60.Pn

Opis:

Melt-spun ribbons were produced from the Pr₈Dy₁Fe₆₀Co₇Mn₆B₁₄Zr₁Ti₃ base alloy at the surface velocity of the cooper wheel of 30 m/s. The studies showed amorphous structure of ribbons and their soft magnetic properties. X-ray diffraction was used to determine phase constitution of all obtained samples. Annealing of ribbons caused formation of nanocomposite structure, which was a result of coexistence of hard magnetic RE₂(Fe,Co)₁₄B and soft magnetic α-Fe phases. Basic magnetic properties such as: coercivity $\text{}_{J}H_{c}$, remanence $J_{r}$ and maximum energy product $(BH)_\text{max}$ were determined from the measured hysteresis loops. The microstructure of selected specimens was observed by transmission electron microscopy technique.

Źródło:

Acta Physica Polonica A; 2015, 128, 1; 94-97
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 75.

Tytuł:

Study of Si-Implanted and Thermally Annealed Layers of Silicon by Using X-ray Grazing Incidence Methods

Autorzy:

Klinger, D.
Lefeld-Sosnowska, M.
Pełka, J. B.
Paszkowicz, W.
Gierłowski, P.
Pankowski, P.

Powiązania:

https://bibliotekanauki.pl/articles/2030709.pdf

Data publikacji:

2002-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.10.-i
61.10.Kw
61.72.Tt
68.35.Fx
81.40.Ef
81.65.Mq

Opis:

This paper reports on the study of structural modifications induced by the implantation process and by the subsequent thermal annealing in near-surface layers of Si single crystals implanted with Si$\text{}^{2+}$ ions of energy 140 keV and doses from 1×10$\text{}^{15}$ to 1× 10$\text{}^{16}$ ions/cm$\text{}^{2}$. The grazing incidence X-ray diffraction and X-ray reflectivity measurements were applied to determine the thickness and structural composition of the damaged layers. The fitted electron density profiles indicated an existence of an interfacial layer with density higher than the density of Si matrix or near-surface oxide layer. Formation of polycrystalline phases of silicon and silicon oxides is discussed in dependence on the conditions of annealing treatment and implantation dose.

Źródło:

Acta Physica Polonica A; 2002, 101, 5; 795-801
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 76.

Tytuł:

Quantum Control of Motional States of Neutral Atoms: Exploiting the External Degrees of Freedom

Autorzy:

Bigelow, N. P.
Chałupczak, W.
Ejnisman, R.
Pu, H.
Rudy, P.
Shaffer, J.

Powiązania:

https://bibliotekanauki.pl/articles/1968501.pdf

Data publikacji:

1998-01

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

03.75.Fi
32.80.Pj
42.50.Dv

Opis:

As research in quantum optics has advanced, so too has our ability to precisely tailor the quantum state of a system. Indeed, techniques for quantum state preparation have become sufficiently advanced that an entire subfield has appeared which has been given the name "quantum control". Parallel to these advances have been other striking developments in quantum optics, in particular, laser cooling and trapping of neutral atoms. In this paper we describe some of the recent advancements in laser cooling, particularly in our laboratories, and point out that laser cooling and trapping is also realizing an important form of quantum control. In laser cooling, instead of exercising control over the internal quantum state of an atom or molecule or a laser field, we are instead controlling a complementary set of degrees of freedom: those of the external coordinates of the atom.

Źródło:

Acta Physica Polonica A; 1998, 93, 1; 11-29
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 77.

Tytuł:

Investigation of As Grown and Induced Structural Defects in SrLaXO$\text{}_{4}$ (x = Al, Ga) Crystals

Autorzy:

Ryba-Romanowski, W.
Gołąb, S.
Dereń, P.
Dominiak-Dzik, G.
Pisarski, W.
Gloubokov, A.

Powiązania:

https://bibliotekanauki.pl/articles/1964366.pdf

Data publikacji:

1997-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.55.Hx
42.70.Hj

Opis:

SrLaGaO$\text{}_{4}$ and SrLaAlO$\text{}_{4}$ substrates grown by the Czochralski method have no twins or subgrains however they show strong tendency to form point defects. The nature of these defects is not well understood yet. They may be associated with deviations from stoichiometry andor oxygen atoms located in the interstitial positions. Virtually all title crystals grown by the Czochralski method display various colours from light green to deeply red owing to light absorption by point defects. Absorption centres appear to be very stable in time and resistant to usual thermal treatment. UV excitation increases the density of defects and gives rise to strong photoluminescence, otherwise too weak to be observed.

Źródło:

Acta Physica Polonica A; 1997, 92, 1; 191-196
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 78.

Tytuł:

Anharmonic Optical Phonon Effects in ZnO Nanocrystals

Autorzy:

Khusnutdinov, S. V.
Dynowska, E.
Zaleszczyk, W.
Makhniy, V. P.
Wysmołek, A.
Korona, K. P.

Powiązania:

https://bibliotekanauki.pl/articles/2048106.pdf

Data publikacji:

2011-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.61.Ga
74.25.nd
63.20.kg

Opis:

Zinc oxide (ZnO) is a very promising material for optoelectrical devices operating at the short-wavelength end of the visible spectral range and at the near UV. The Raman scattering studies of ZnO heterolayers formed by isothermal annealing show sharp phonon lines. In addition to the A$\text{}_{1}$(TO), E$\text{}_{1}$(TO), E$\text{}_{2}^{H}$, and E$\text{}_{1}$(LO) one-phonon lines, we observed two-phonon lines identified as: E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$, E$\text{}_{2}^{H}$ + E$\text{}_{2}^{L}$, and 2LO at 332, 541, and 1160 cm$\text{}^{-1}$, respectively (at room temperature). The identification of the E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$ peak was confirmed by its thermal dependence. Temperature dependent measurements in the range 6-300 K show that the phonon frequencies decrease with temperature. The E$\text{}_{2}^{H}$ peak is at energy 54.44 meV (439.1 cm$\text{}^{-1}$), at 4 K and due to phonon-phonon anharmonic interaction, its energy decreases to 54.33 meV (438.2 cm$\text{}^{-1}$) at room temperature. The Grüneisen parameter found for this oscillation mode was γ$\text{}_{E}$ 2H = 1.1 at about 300 K. The intensity of the E$\text{}_{2}^{H}$ - E$\text{}_{2}^{L}$ peak increases strongly with temperature and this dependence can be described by the Bose-Einstein statistics with activation energy of 13.8 meV (nearly equal to the energy of the E$\text{}_{2}^{L}$ phonon).

Źródło:

Acta Physica Polonica A; 2011, 119, 5; 678-680
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 79.

Tytuł:

Temperature Dependence ofĝ Tensor Anisotropy in (tm-p-PD):Chloranil, Charge Transfer Complex Powders

Autorzy:

Grampp, G.
Sczaniecki, P. B.
Żurek, S.
Bednarski, W.

Powiązania:

https://bibliotekanauki.pl/articles/2043604.pdf

Data publikacji:

2005-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

76.30.Rn

Opis:

The powders of 2,3,5,6-tetramethyl-p-phenylenediamine:chloranil charge transfer complex were studied by EPR. Numerical pack EPR-NMR was used to simulate and fit the X-band experimental data in the temperature range of 119-298 K. Very good agreement between the experiment and simulations permits to obtain the main values ofĝ matrix and plot their temperature dependence. At 150 K the main g values are g$\text{}_{xx}$=g$\text{}_{yy}$=2.0041 and g$\text{}_{zz}$=2.0015. g splitting factor varies significantly with temperature and shows an anomaly near 200 K. The signal narrows with the temperature increase, which agrees with the earlier observation. Individual component linewidth, used in the simulation is anisotropic and amounts to 0.1-0.8 mT; which is reasonable when compared with those measured earlier for the single crystals of p-phenylenediamine:chloranil, where the narrowest lines are quoted to be 18μT.

Źródło:

Acta Physica Polonica A; 2005, 108, 2; 317-321
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 80.

Tytuł:

ESR and Electron Spin Echo Studies of Spin-Lattice Relaxation of Hydrazinium Radical in Li(N$\text{}_{2}$H$\text{}_{5}$)O$\text{}_{4}$ Single Crystal

Autorzy:

Morawski, P.
Hoffmann, S. K.
Hilczer, W.
Goslar, J.

Powiązania:

https://bibliotekanauki.pl/articles/1964224.pdf

Data publikacji:

1997-06

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.80.Ed
76.30.Rn

Opis:

A hydrazinium ṄH-NH$\text{}_{3}^{+}$ radical was identified by ESR in γ-irradiated Li(N$\text{}_{2}$H$\text{}_{5}$)SO$\text{}_{4}$ single crystal. Unpaired electron is strongly localized on the nitrogen atom as compared to hydrazinium radicals in other crystals. Angular variations of the multicomponent ESR spectra and computer calculations gave the isotropic hyperfine coupling parameters (in mT): a$\text{}_{N1}$ = 1.93, a$\text{}_{N2}$ = 0.80, a$\text{}_{H1}$ = 2.50, a$\text{}_{H1'}$ = 0.48 (NH$\text{}_{3}$), and a$\text{}_{H2}$ = 1.40 (adjacent molecule). The radiation defects containing unpaired electrons do not influence much the protonic conductivity along the hydrazine molecule chains in the crystal. It confirms a tunelling mechanism of the conductivity activated by NH$\text{}_{2}$-group rotation. Spin-lattice relaxation time T$\text{}_{1}$ varies strongly with temperature in the range from 100 ms (10 K) to 90 μs (170 K) and is governed by spectral diffusion (1/T$\text{}_{1}$ ∝ T$\text{}^{2}$) and a Murphy-type mechanism (1/T$\text{}_{1}$ ∝ cosech(Δ/T)) with Δ = 150 cm$\text{}^{-1}$. A distribution of the spin-relaxation times was observed with temperature independent dispersion parameter β = 0.76.

Źródło:

Acta Physica Polonica A; 1997, 91, 6; 1121-1129
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 81.

Tytuł:

EPR and Impedance Measurements of Graphene Oxide and Reduced Graphene Oxide

Autorzy:

Kempiński, M.
Łoś, S.
Florczak, P.
Kempiński, W.
Jurga, S.

Powiązania:

https://bibliotekanauki.pl/articles/1033701.pdf

Data publikacji:

2017-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

72.80.Vp
76.30.-v

Opis:

We report the observations of electron paramagnetic resonance and impedance measurements of graphene oxide and reduced graphene oxide performed in the wide temperature range in order to get insight into the electronic properties of graphene-based materials and the role of oxygen functionalities in the charge carrier transport phenomena. In such systems the strong spin localization, hopping charge carrier transport as well as the formation of adsorption layers are observed, all the phenomena changing significantly after the heavily oxidized graphene is reduced.

Źródło:

Acta Physica Polonica A; 2017, 132, 1; 81-85
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 82.

Tytuł:

Structure properties of AlSi7Mg/SiC composite produced by stir casting method

Autorzy:

Cyboroń, J.
Karolus, M.
Putyra, P.
Dyzia, M.
Ratuszek, W.

Powiązania:

https://bibliotekanauki.pl/articles/1111951.pdf

Data publikacji:

2016-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.65.Ps
83.85.Hf
81.05.Mh

Opis:

The paper presents the structure studies on composites of aluminum alloy matrix with addition of silicon carbide phase (from 5 to 15 vol.% SiC and 10 vol.% SiC + 10 vol.% graphite) obtained by the stir casting method. The aim of this work is to determine the influence of the SiC content and electrical discharge machining processes on the phase composition, microstructure, and values of residual stresses. In order to determine the heterogeneity of the obtained materials, the X-ray diffraction analysis was performed in different sample orientations to the direction of the X-ray beam (perpendicular and parallel), using different geometries (the Bragg-Brentano and grazing incident X-ray diffraction). This work presents the results of the residual stress analysis in the tested composites generated by various content of SiC additives. Residual stresses were determined by both of the ın²ψ and g-ın²ψ X-ray methods. Obtained results shown the significant gradient of residual stress in all cases.

Źródło:

Acta Physica Polonica A; 2016, 130, 4; 969-971
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 83.

Tytuł:

Crystalline Structure, Stoichiometry and Magnetic Properties of the Morasko Meteorite

Autorzy:

Idzikowski, B.
Kováč, J.
Diko, P.
Stankowski, W.
Muszyński, A.

Powiązania:

https://bibliotekanauki.pl/articles/1535541.pdf

Data publikacji:

2010-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

91.65.Sn
75.50.Bb
67.80.dk

Opis:

The composition and structure of iron-nickel alloys smithereens extracted from the Morasko (Poland) Meteorite (fell ∿ 5 ka BP) were investigated by optical metallographic techniques, scanning electron microscopy and electron microprobe analysis, thermal analyses, magnetic measurements and X-ray diffraction. Microstructural analysis by scanning electron microscopy and optical microscopy has shown that the sample is composed from large grains of Fe-Ni alloy in which secondary phase crystals with well developed crystal habits and the size about 10 micrometers are distributed. Thermal analyses confirmed that the transformation from alpha to gamma Fe-Ni solid solution appearing as a function of temperature corresponds to about 5 wt% Ni in the Fe-Ni alloy. Possible scenario of the extraterrestrial sample solidification is related to the microstructural and magnetic behavior.

Źródło:

Acta Physica Polonica A; 2010, 118, 5; 1071-1073
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 84.

Tytuł:

Resonant Plasmon Response of a Periodically Modulated Two-Dimensional Electron Gas

Autorzy:

Sznajder, P.
Piętka, B.
Szczytko, J.
Łusakowski, J.
Bardyszewski, W.

Powiązania:

https://bibliotekanauki.pl/articles/1409611.pdf

Data publikacji:

2012-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

52.25.Mq
52.40.Db
73.20.-r
71.10.Ca
73.20.Mf

Opis:

We report the theoretical study of the optical response of a periodically modulated two-dimensional electron gas. The density of states is calculated within the first order of the perturbation theory and the effects of the short-range disorder are explained and discussed. We demonstrate that the magnetic field values corresponding to the characteristic narrowing of the density of states width are given by the zeros of the subsequent Laguerre polynomials. The observed increase of the density of states at the edges are interpreted as van Hove singularities. The broadening effects are shown to modify and smear out the observed effects with increasing temperature above 2 K. The plasmon dispersion relation is discussed in terms of the random phase approximation. Small changes in plasmon dispersion relation related to the periodic modulation were predicted.

Źródło:

Acta Physica Polonica A; 2012, 122, 6; 1090-1092
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 85.

Tytuł:

Temperature Cross-Sensitivity for Highly Refractive Index Sensitive Nanocoated Long-Period Gratings

Autorzy:

Grochowski, J.
Myśliwiec, M.
Mikulic, P.
Bock, W.
Śmietana, M.

Powiązania:

https://bibliotekanauki.pl/articles/1399344.pdf

Data publikacji:

2013-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.70.Ce
42.79.Gn
07.07.Df
81.20.Fw

Opis:

There is a demand for highly refractive index sensitive devices simultaneously insensitive to temperature (T) changes. We investigate both T and refractive index sensitivity of long-period gratings coated with 100 nm thin high refractive index (n ≈ 1.9 at λ = 1550 nm) silicon nitride $(SiN_{x})$ film. The long-period gratings with period of 500 μm were induced in standard Corning SMF28 fibre using electric arc and nanocoated with $SiN_{x}$ by radio frequency plasma enhanced chemical vapour deposition method. As a sensorial effect we investigated resonance shift with temperature variations (from 30 to 70°C) for measurement in deionized water ($n_{D}$ = 1.33) and glycerine ($n_{D}$ = 1.46). In case of measurements in water for resonance observed at λ = 1510 nm, refractive index sensitivity of - 85 nm/RIU and temperature sensitivity of 0.09 nm/C $(H_2O)$ were obtained which gives refractive index-T sensitivity ratio (RI/T) of - 944°C/RIU. Refractive index and T sensitivity of sensor covered with $SiN_{x}$ film increased to - 618 nm/RIU and 0.22 nm/°C, respectively. Thanks to nanocoating deposition, refractive index-T sensitivity ratio was improved by factor of 3. In case of measurements in glycerine significant influence of glycerine's thermo-optic coefficient on obtained results was observed. It is worth noticing that $SiN_{x}$ coating stabilizes sensing behaviour of the sensor.

Źródło:

Acta Physica Polonica A; 2013, 124, 3; 421-424
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 86.

Tytuł:

Magnetic Field Sensor Based on Magnetic Tunnel Junction with Voltage-Tunable Magnetic Anisotropy

Autorzy:

Skowroński, W.
Wiśniowski, P.
Wrona, J.
Żywczak, A.
Stobiecki, T.

Powiązania:

https://bibliotekanauki.pl/articles/1386807.pdf

Data publikacji:

2015-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

85.75.-d
85.75.Ss
85.35.-p

Opis:

We present a submicron magnetic field sensor with voltage-tunable magnetic field sensitivity. The device, based on magnetic tunnel junction, exhibits high tunnelling magnetoresistance ratio of up to 90%. Perpendicular magnetic anisotropy of thin ferromagnetic sensing layer in combination with an in-plane magnetized reference layer is used to obtain linear change in the sensor resistance in response to the in-plane magnetic field. The perpendicular anisotropy is further controlled by the bias voltage and, thus, the sensitivity of the sensor is changed. In addition, we evaluate the sensor selectivity for the magnetic field direction and present an influence of the temperature on the anisotropy.

Źródło:

Acta Physica Polonica A; 2015, 127, 2; 496-498
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 87.

Tytuł:

X-Ray Diffraction Investigations of NdGaO$\text{}_{3}$ Single Crystal

Autorzy:

Mazur, K.
Sass, J.
Giersz, W.
Reiche, P.
Schell, N.

Powiązania:

https://bibliotekanauki.pl/articles/1964526.pdf

Data publikacji:

1997-07

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

81.10.Fq
61.50.Ks
68.35.Bs

Opis:

Neodymium gallium perovskite single crystals grown with the Czochralski method were examined with several complementary X-ray methods. By means of X-ray diffraction topography and reciprocal space diagram the structural perfection and crystal homogeneity of the studied wafers were determined. Additionally, the results of the X-ray reflectometry investigations of the surface perfection after the mechanochemical treatment are presented.

Źródło:

Acta Physica Polonica A; 1997, 92, 1; 226-230
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 88.

Tytuł:

Cathodoluminescence Study of Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te and Zn$\text{}_{1-x}$Mn$\text{}_{x}$Te

Autorzy:

Hołda, A.
Rodzik, A.
Melnikov, A. A.
Żukowski, P. W.

Powiązania:

https://bibliotekanauki.pl/articles/1933757.pdf

Data publikacji:

1995-10

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.60.Hk
78.55.Et

Opis:

The cathodoluminescence spectra for Cd$\text{}_{1-x}$Μn$\text{}_{x}$Te (0 < x ≤ 0.7) and Zn$\text{}_{1-x}$Mn$\text{}_{x}$Te (0 < x ≤ 0.6) at room and liquid nitrogen temperature have been presented and discussed. Especially, the influence of increasing temperature and Mn content on cathodoluminescence spectra. The cathodoluminescence emission in Ζn$\text{}_{1-x}$Mn$\text{}_{x}$Te (Cd$\text{}_{1-x}$Μn$\text{}_{x}$Te) centered at ≈ 1.95 eV (2.0 eV) and ≈ 2.2 eV (2.5 eV) are ascribed to Stokes-shifted $\text{}^{4}$Τ$\text{}_{1}$($\text{}^{4}$G) → $\text{}^{6}$A$\text{}_{1}$($\text{}^{6}$S) and $\text{}^{4}$Τ$\text{}_{2}$($\text{}^{4}$G) → $\text{}^{6}$A$\text{}_{1}$($\text{}^{6}$S) internal transitions of Mn$\text{}^{+2}$ within the 3d$\text{}^{5}$ state, respectively.

Źródło:

Acta Physica Polonica A; 1995, 88, 4; 739-742
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 89.

Tytuł:

Formation Time of Magnetic Polarons

Autorzy:

Dietl, T.
Peyla, P.
Grieshaber, W.
Merle d'Aubigné, Y.

Powiązania:

https://bibliotekanauki.pl/articles/1872800.pdf

Data publikacji:

1995-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.47.+p
78.55.Et
75.50.Rr

Opis:

It is shown that non-scalar spin-spin interactions rather than spin-lattice coupling or spin diffusion control the dynamics of the magnetization formation visible in time-resolved luminescence and SQUID magnetometry.

Źródło:

Acta Physica Polonica A; 1995, 87, 2; 361-364
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 90.

Tytuł:

Density of Gap States Deconvoluted from Photoconductive Spectra for Undoped Amorphous Silicon and Silicon-Carbon Thin Films

Autorzy:

Pisarkiewicz, T.
Stapiński, T.
Adriaenssens, G.
Lauwerens, W.
Rava, P.

Powiązania:

https://bibliotekanauki.pl/articles/1873043.pdf

Data publikacji:

1995-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

73.20.Dx

Opis:

Density of states in amorphous hydrogenated silicon and silicon-carbon thin films were calculated by deconvolution of the optical absorption coefficient a! measured by constant photocurrent method. Addition of carbon to silicon lattice increases the optical band-gap and influences the distribution of defect states in the gap.

Źródło:

Acta Physica Polonica A; 1995, 87, 2; 407-410
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 91.

Tytuł:

Time-Resolved Studies of Excitonic Dynamics in a Wide II-VI Quantum Well by a Femtosecond Pump-Probe Reflectivity

Autorzy:

Trajnerowicz, A.
Golnik, A.
Kossacki, P.
Pacuski, W.
Wojtowicz, T.

Powiązania:

https://bibliotekanauki.pl/articles/2047018.pdf

Data publikacji:

2006-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.67.De
71.35.Pq
78.47.+p

Opis:

We present time-dependent reflectance spectra of wide (Cd,Mn)Te/(Cd,Mg)Te quantum wells. Interactions between excitons, trions, and carriers are studied for exciton densities up to 10$\text{}^{11}$ cm$\text{}^{-2}$. The resonant excitation at different excitonic lines is analyzed.

Źródło:

Acta Physica Polonica A; 2006, 110, 3; 395-401
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 92.

Tytuł:

Femtosecond Dynamics of Neutral and Charged Exciton Absorption in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te Quantum Well

Autorzy:

Płochocka, P.
Kossacki, P.
Maślana, W.
Radzewicz, C.
Gaj, J. A.
Cibert, J.
Tatarenko, S.

Powiązania:

https://bibliotekanauki.pl/articles/2035611.pdf

Data publikacji:

2002

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

78.40.Fy
78.47.+p
78.67.De

Opis:

We present a study of time-dependent transmission spectra of a modulation-doped Cd$\text{}_{1-x}$Mn$\text{}_{x}$Te/Cd$\text{}_{1-y-z}$Zn$\text{}_{y}$Mg$\text{}_{z}$Te quantum well with variable hole gas concentration. We study the influence of pump pulses on excitonic absorption in subpicosecond time scale. A spectrally broad probe pulse of duration of 40 femtoseconds was used to record the absorption spectra at controlled delay. Studies of temporal evolution of exciton energies revealed coherence decay of linearly polarized excitons and thermalization of non-equilibrium exciton states. We found that a characteristic timescale for thermalization of non-equilibrium populations of photocreated excitons is between 0.8 and 3.6 ps. The timescale of this process depends on the hole concentration in quantum well: for higher hole concentration the decay is faster. Long-lived photo-induced magnetization accompanied by heating of the magnetic system was also observed.

Źródło:

Acta Physica Polonica A; 2002, 102, 4-5; 679-686
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 93.

Tytuł:

Deep Level Studies in Zn$\text{}_{1-x}$Mg$\text{}_{x}$Se Layers Grown by MBE

Autorzy:

Płachetko, S.
Ząbik, G.
Łukasiak, Z.
Borowski, P.
Bała, W.

Powiązania:

https://bibliotekanauki.pl/articles/1992065.pdf

Data publikacji:

1998-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.55.Eq
72.80.Ey

Opis:

The deep levels present in semiconducting Zn$\text{}_{1-x}$Mg$\text{}_{x}$Se (0 ≤ x ≤ 0.4) were investigated by means of deep level transient spectroscopy, photocapacitance transient and thermally stimulated depolarization. The thermal activation energy levels estimated from the deep level transient spectroscopy measurements are: E$\text{}_{T1}$=0.28 eV and E$\text{}_{T2}$=0.56 eV. For the Zn$\text{}_{1-x}$Mg$\text{}_{x}$Se epilayers thermally stimulated depolarization curves consist of four overlapping peaks: 227.4 K, 243.6 K, 265.7 K, and 285.0 K.

Źródło:

Acta Physica Polonica A; 1998, 94, 3; 483-486
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 94.

Tytuł:

Spin Polaron-Bipolaron Scenario of Three Gap-Like Energy Scales in Superconducting Cuprates

Autorzy:

Wróbel, P.
Maciąg, A.
Suleja, W.
Eder, R.
Micnas, R.

Powiązania:

https://bibliotekanauki.pl/articles/1536806.pdf

Data publikacji:

2010-08

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

74.20.Mn
74.72.Kf

Opis:

We argue that three gaps observed in underdoped cuprates can be attributed to the formation of antiferromagnetic spin polarons and bipolarons. Within the spin polaron scenario the antinodal pseudogap at he high energy scale originates from the change of the Fermi surface topology, induced by antiferromagnetic correlations. That change gives rise to the diminishing of the spectral weight at the antinodal region near the Brillouin zone boundary. We demonstrate that effect by analyzing effective models of doped antiferromagnets. The second type of pseudogap appearing at the intermediate energy scale originates from the phenomena which are precursory to superconductivity and predominantly concern the portion of the Fermi surface near the nodal region. In order to analyze the latter phenomenon we use the negative U Hubbard model, in which many details typical to spin polaron physics are neglected, but which contains the essential ingredient of it, that is the strong short range attraction. The lowest energy scale is related to the true superconducting gap which develops with doping, although both types of pseudogap diminish with doping. This behavior can be explained by the fact that the spin polaron band is empty in the undoped system and therefore the formation of the superconducting state in the system is forbidden. Due to a pedagogical character of this report, we present in the introduction a short overview of mostly recent experimental results which are related to the gap-pseudogap physics.

Źródło:

Acta Physica Polonica A; 2010, 118, 2; 292-298
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 95.

Tytuł:

Multispectral Systems of Imaging Scenery in Critical Infrastructure Protection, Threat Identification and Recognition

Autorzy:

Karol, M.
Szustakowski, M.
Życzkowski, M.
Markowski, P.
Ciurapiński, W.

Powiązania:

https://bibliotekanauki.pl/articles/1399365.pdf

Data publikacji:

2013-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

42.30.Wb
87.57.-s
42.79.Qx

Opis:

The surveillance system more often uses devices working on different bands that are used not only for detection but also to recognize and identify threats. The paper presents the possibility of protection, detection and identification of risks, achieved through the use of multispectral detection systems in critical infrastructure facilities. The authors consider the benefits of active sensors based on other wavebands, such as millimeter wave radar, terahertz cameras, infrared camera and shows the ability to detect and identify the target using data collected by the sensors. Also discussed the issue of fusion data from different sensors and opportunities that the whole system obtained by application of data fusion.

Źródło:

Acta Physica Polonica A; 2013, 124, 3; 459-462
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 96.

Tytuł:

Electronic Structure and Magnetic Properties of $Ce_5CuPb_3$ Based on Ab Initio Calculations

Autorzy:

Werwiński, M.
Szajek, A.
Leśniak, P.
Malinowski, W.
Stasiak, M.

Powiązania:

https://bibliotekanauki.pl/articles/1427552.pdf

Data publikacji:

2012-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.20.-b
75.25.-j

Opis:

$Ce_5CuPb_3$ band structure has been calculated based on two ab initio methods: full potential-linearized augmented plane wave implemented in WIEN2k code and full-potential local-orbital minimum-basis in FPLO code. The calculations were performed with and without spin polarization. Starting from the generalized gradient approximation we additionally tested either an orbital polarization correction and the GGA+U approach with the Coulomb repulsion energies U varied from 0 to 6.7 eV within the Ce 4f electron shell. The calculations confirmed possible antiparallel alignment of the magnetic moments of the cerium atoms in the low temperature phase.

Źródło:

Acta Physica Polonica A; 2012, 121, 5-6; 1182-1184
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 97.

Tytuł:

The Influence of Pressure on the Roughness of InGaP Layers

Autorzy:

Dumiszewska, E.
Knyps, P.
Wesolowski, M.
Teodorczyk, M.
Strupinski, W.

Powiązania:

https://bibliotekanauki.pl/articles/1492628.pdf

Data publikacji:

2011-12

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

77.55.dj
78.30.Fs
73.61.Ey
81.10.-h

Opis:

Today, the technology of typical silicon-solar cells is fully developed and mature. In spite of its continuous improvements, the record efficiencies of 25.0% are approaching theoretical solar conversion limits of around 33.7%. Values much beyond this limit are likely to be achieved using III-V semiconductor compounds, electrical and optical properties are more suitable for solar energy conversion. They are the most promising candidates for realizing solar cells, which can achieve efficiencies of 50% and more. In this paper we studied the influence of pressure in the reactor chamber on the roughness of an InGaP "nucleation layer" grown on Ge. The growth of the layers was performed in a metalorganic vapour phase epitaxy reactor AIX 200/4. The source gases were trimethylgallium, trimethylindium and $AsH_3$. The rate of pressure in the reactor was raised from 100 mbar to 400 mbar by 50 mbar. The InGaP layers with the lowest roughness were achieved at the pressure of 400 mbar. The layers were characterized by very low roughness (RMS < 0.3) measured by atomic force microscopy. The quality of the surface was perfect enough to be applied in a solar cell structure.

Źródło:

Acta Physica Polonica A; 2011, 120, 6A; A-050-A-051
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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Skocz do pozycji: 98.

Tytuł:

Polymeric Track Etched Membranes - Application for Advanced Porous Structures Formation

Autorzy:

Sartowska, B.
Starosta, W.
Apel, P.
Orelovitch, O.
Blonskaya, I.

Powiązania:

https://bibliotekanauki.pl/articles/1400430.pdf

Data publikacji:

2013-05

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

61.82.Pv
81.16.Be
81.05.Rm
61.43.Gt

Opis:

Track etched membranes are porous systems consisting of a thin polymer foil with channels from surface to surface. Latent ion tracks are the result of the passage of swift ions through solid matter and they can be etched selectively. As a result, conical, cylindrical or other shape channels can be obtained. The increasing interest in the polymer track etched membranes with nanochannels is connected with development and creation of nanoporous materials of unique properties. The template synthesis method based on deposition of materials inside well-defined uniform pores of membranes offers unique possibilities of formation of one-dimensional, high aspect ratio (length to diameter) cylindrical species having form of rods, wires, tubules, multiwall tubules and multilayer rods, practically from any solid material. Metal-organic frameworks are a class of hybrid materials comprising metal ion-based vertices and organic ligands (linkers) which serve to connect the vertices into one-, two- or three-dimensional periodic structures. A specific property of porous structures is their intrinsic porosity, which renders them potentially useful for gas storage, separation and catalysis. The possibility of obtaining a new composite material: polymeric track etched membrane with pores filled with hybrid porous material has been demonstrated.

Źródło:

Acta Physica Polonica A; 2013, 123, 5; 819-821
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 99.

Tytuł:

Photoluminescence Dynamics of CdSe Quantum Dot with Single $Mn^{2+}$ Ion under Modulated Excitation

Autorzy:

Pilat, M.
Goryca, M.
Smoleński, T.
Pacuski, W.
Kossacki, P.

Powiązania:

https://bibliotekanauki.pl/articles/1377238.pdf

Data publikacji:

2014-11

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

75.75.Jn
78.47.jd
78.67.Hc

Opis:

A quantum dot with a single magnetic ion is a perfect model system to investigate spin dynamics of a magnetic ion embedded in semiconductor matrix. In this work we present results of spin dynamics studies of $Mn^{2+}$ ion embedded in CdSe quantum dot, performed under modulated excitation of the dot. In particular, the relaxation time of the $Mn^{2+}$ ion in high magnetic field was determined.

Źródło:

Acta Physica Polonica A; 2014, 126, 5; 1212-1214
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 100.

Tytuł:

Conductivity Near the Metal-to-Insulator Transition in Cd$\text{}_{1-x}$Mn$\text{}_{x}$Se:Sc

Autorzy:

Głód, P.
Sawicki, M.
Lenard, A.
Dietl, T.
Plesiewicz, W.

Powiązania:

https://bibliotekanauki.pl/articles/1887158.pdf

Data publikacji:

1991-02

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

71.30.+h
71.55.Jv

Opis:

Earlier studies of transition metal impurities in II-VI compounds suggest that Sc acts as a resonant donor. We performed Hall effect and conductivity measurements of CdSe:Sc and Cd$\text{}_{0.95}$Mn$\text{}_{0.05}$Se:Sc. The results, particularly the critical concentration of the metal-to-insulator transition, turned out to be similar to those obtained previously for Cd$\text{}_{1-x}$Mn$\text{}_{x}$Se doped with hydrogenic-like impurities, such as In and Ga. Therefore, if the ground state of Sc impurity is indeed located above the bottom of the conduction band, our data demonstrate that the metal-to-insulator transition is primarily driven by the scattering, i.e. it corresponds to the Anderson localization.

Źródło:

Acta Physica Polonica A; 1991, 79, 2-3; 389-392
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

/5

Artykuł

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