Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "71.70.-d" wg kryterium: Temat


Wyświetlanie 1-27 z 27
Tytuł:
Crystal-Field Origin of the Giant Magnetocrystalline Anisotropy of PrRu$\text{}_{2}$Si$\text{}_{2}$
Autorzy:
Michalski, R.
Ropka, Z.
Radwański, R. J.
Powiązania:
https://bibliotekanauki.pl/articles/2013368.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.-d
71.20.Eh
Opis:
PrRu$\text{}_{2}$Si$\text{}_{2}$ shows ferromagnetism below 14 K with the ordered moment of 2.7μ$\text{}_{B}$. It exhibits an enormous magnetic anisotropy at 4.2 K with the anisotropy field of about 400 T. We have attrributed the magnetism of PrRu$\text{}_{2}$Si$\text{}_{2}$ to the Pr$\text{}^{3+}$ ions. Thus we performed calculations of the fine electronic structure of the Pr$\text{}^{3+}$ ion in the tetragonal symmetry, relevant to PrRu$\text{}_{2}$Si$\text{}_{2}$, taking into account crystal-field and inter-site exchange interactions. Our calculations reproduce well the zero-temperature moment, the single-crystalline magnetization curves, and giant anisotropy field as 400 T. The magnetocrystalline-anisotropy energy K$\text{}_{1}$ of 59 J/cm$\text{}^{3}$ is the largest known anisotropy - the anisotropy energy of the Nd$\text{}_{2}$Fe$\text{}_{14}$B supermagnet amounts to 12.5 J/cm$\text{}^{3}$ only. Unfortunately, this giant anisotropy is confined to low temperatures only which prohibits its technical applications in the permanent-magnet industry.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 767-770
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Specific Heat of Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te
Autorzy:
Górska, M.
Łusakowski, A.
Jędrzejczak, A.
Gołacki, Z.
Anderson, J. R.
Balci, H.
Powiązania:
https://bibliotekanauki.pl/articles/2038143.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.-d
75.40.Cx
Opis:
The temperature dependence of the magnetic specific heat was studied experimentally and theoretically in the semimagnetic semiconductor Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te for x=0.027 and x=0.073, over the temperature range from 0.5 K to 15 K, in magnetic fields up to 2 T. In zero magnetic field at about 2 K there was a broad maximum in the magnetic specific heat, which was much higher than that predicted by the model of superexchange interaction between nearest neighbors; the maximum values increased with magnetic field. The experimental data were analyzed in the framework of a model which takes into account the spin splitting of the ground state of a single Eu2+ ion in the presence of local lattice distortions in the Pb$\text{}_{1-x}$Eu$\text{}_{x}$Te mixed crystal. The model describes well the experimental data, especially for lower x-values, where the contribution from singlets dominates.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 631-636
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Periodic Behavior of the Exciton Oscillator Strength with AlAs Thickness in Type II GaAs AlAs Heterostructures
Autorzy:
Gourdon, C.
Martins, D.
Lavallard, P.
Ivchenko, E. L.
Powiązania:
https://bibliotekanauki.pl/articles/2028741.pdf
Data publikacji:
2001-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.66.-w
71.70.-d
Opis:
For a single GaAs/AlAs/GaAs type II pseudodirect double quantum well, as well as for superlattices it was predicted that the oscillator strength of the lowest optical transition has a periodic dependence on the number of AlAs monolayers. The oscillator strength depends on the coupling between theΓ and X electron states. We use samples containing a single GaAs/AlAs/GaAs double quantum well with thickness gradient to show experimental evidence of this effect. The results concerning theΓ-X coupling are obtained from the study of the ratio of photoluminescence intensities of the zero-phonon line and the phonon replica and from their time decay. They show the monolayer dependence of the Γ-X mixing potential. We extend the model describing the Γ-X coupling for ideal interfaces in the frame of the envelope approximation to the case of non-abrupt interfaces and exciton localization. The amplitude of variation of the radiative recombination time due to the Γ-X mixing is well reproduced within this model.
Źródło:
Acta Physica Polonica A; 2001, 100, 3; 409-416
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Structure of Zinc-Blende Zn$\text{}_{0.5}$Co$\text{}_{0.5}$Se: Theoretical Study
Autorzy:
Hołda, A.
Markowski, R.
Dębowska, D.
Kisiel, A.
Zimnal-Starnawska, M.
Piacentini, M.
Zema, N.
Lama, F.
Powiązania:
https://bibliotekanauki.pl/articles/1950806.pdf
Data publikacji:
1996-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.-b
71.20.Cf
71.70.-d
Opis:
In this paper we present partial densities of states for spin-polarized antiferromagnetic phase of Zn$\text{}_{0.5}$Co$\text{}_{0.5}$Se as well as schematic layouts of the bands, obtained using the ab initio self-consistent semi-relativistic linear muffin tin orbital method. We also present, from theoretical point of view, the analysis of influence of the transition metal cobalt on the electronic structure of a pure ZnSe.
Źródło:
Acta Physica Polonica A; 1996, 90, 4; 817-820
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic Structure of Zinc-Blende Zn$\text{}_{0.5}$V$\text{}_{0.5}$Se: Theoretical Study
Autorzy:
Markowski, R.
Hołda, A.
Dębowska, D.
Kisiel, A.
Zimnal-Starnawska, M.
Piacentini, M.
Zema, N.
Lama, F.
Powiązania:
https://bibliotekanauki.pl/articles/1934068.pdf
Data publikacji:
1995-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.-b
71.70.-d
71.20.Cf
Opis:
In this paper we present a comprehensive study of electronic structure of Zn$\text{}_{0.5}$V$\text{}_{0.5}$Se from the theoretical point of view. Partial and total density of states for spin-polarized antiferromagnetic phase of Zn$\text{}_{0.5}$V$\text{}_{0.5}$Se as well as schematic layouts of the bands have been obtained using the ab initio self-consistent semirelativistic linear muffin-tin orbital method.
Źródło:
Acta Physica Polonica A; 1995, 88, 5; 1023-1027
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indications for Diamagnetic Shift in the Ground State of Boron in Silicon
Autorzy:
Stöhr, M.
Chroboczek, J. A.
Powiązania:
https://bibliotekanauki.pl/articles/1891427.pdf
Data publikacji:
1991-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Ht
71.70.-d
72.20.-i
Opis:
Indications for the observation of the diamagnetic shrinkage of the boron acceptor wave function (WF) in Si are reported. Uniaxial stress (X) was used to split the ground state (GS) of the boron acceptor into two energy levels with spatially complementary WF. The magnetic field selectively induces a shrinking of one of the two WF, depending on whether it is applied parallel or perpendicular to the X axis. As a result, the hopping transitions between lower and higher energy levels are redistributed, leading to significant changes in the activation energy ε$\text{}_{3}$. This effect was borne out by experiment.
Źródło:
Acta Physica Polonica A; 1991, 80, 3; 465-468
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Jahn-Teller Effect: A Pedagogical Approach
Autorzy:
Quéré, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1924301.pdf
Data publikacji:
1993-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.-d
01.30.Rr
61.70.Dx
Opis:
Jahn-Teller effect and Stokes shift are presented in a simple, pedagogical approach adapted to students just starting their course of quantum mechanics. A simple experiment is suggested, which may illustrate and support semi-quantitatively this approach.
Źródło:
Acta Physica Polonica A; 1993, 83, 1; 5-9
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Iron Impurity Related Optical Transitions in HgSe:Fe
Autorzy:
Szuszkiewicz, W.
Julien, C.
Balkanski, M.
Arciszewska, M.
Witkowska, B.
Mycielski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1891323.pdf
Data publikacji:
1991-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Fr
71.70.-d
78.50.Ge
Opis:
Fe$\text{}^{2+}$ crystal field transitions and the heavy hole valence band to the Fe level transitions (e + Fe$\text{}^{3+}$ → Fe$\text{}^{2+}$) have been observed and discussed for HgSe doped with iron.
Źródło:
Acta Physica Polonica A; 1991, 80, 3; 437-440
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exchange Charge Model for $Fe^{3+}:LiAl_{5}O_{8}$
Autorzy:
Vaida, M.
Avram, C.
Powiązania:
https://bibliotekanauki.pl/articles/1791224.pdf
Data publikacji:
2009-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.Ch
78.20.Bh
34.20.Cf
71.70.-d
Opis:
The aim of this paper is the theoretical investigation of $Fe^{3+}$ doped in the ordered phase of $LiAl_{5}O_8$. We used the shell model and pair potential approximation to optimize the geometric structure of $LiAl_{5}O_{8}$. This approach enables the modeling of the crystal field parameters of $LiAl_{5}O_8$ and then calculates the energy levels scheme of $Fe^{3+}$ ions doped in tetrahedral sites in the title crystal. Consistent crystal field analysis and the energy level splittings for $LiAl_{5}O_{8}$ doped with $Fe^{3+}$ ions was performed in the frame of the exchange charge model of crystal field. The comparison of the theoretically obtained results for energy levels with the experimental data, yields satisfactory agreement and confirms the validity of the exchange charge model.
Źródło:
Acta Physica Polonica A; 2009, 116, 4; 541-543
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Band Edge Energies Pinning in Magnetic Field in Semimagnetic $Cd_{0.7}Mn_{0.3}Te$
Autorzy:
Barauskaitė, L.
Brazis, R.
Ivanov, V.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1492778.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Et
75.50.Pp
71.70.-d
Opis:
Results of $Cd_{0.7}Mn_{0.3}Te$ magneto-photoluminescence investigations are analyzed. Photoluminescence was measured in a Voigt geometry at the temperature of 1.6 K. Two models describing radiative transition energy are compared with the experimental results of $Cd_{0.7}Mn_{0.3}Te$ luminescence. The energy of recombination transition, employing the complete form of band states splitting description (term due to the Landau splitting included), shows deviation from experiment at B > 2 T. Two possible reasons of discrepancies from the experiment - exchange interaction constants dependence on magnetic field or band edge energies pinning in magnetic field - are discussed. Band edge energies pinning in magnetic field is related to the hybridization of Mn 3 $d^{5}$ levels with the band states of the host. We determine the corrected values of exchange interaction constants $(N_0 α -N_0 β//3)$ at magnetic fields B < 5 T.
Źródło:
Acta Physica Polonica A; 2011, 120, 6; 1056-1060
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pecularities of p-d Interaction in Semimagnetic Semiconductors with Cr$\text{}^{2+1}$
Autorzy:
Blinowski, J.
Kacman, P.
Powiązania:
https://bibliotekanauki.pl/articles/1890686.pdf
Data publikacji:
1991-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.-m
71.70.-d
Opis:
In cubic DMS crystals with Cr$\text{}^{2+}$ content the non-Heisenberg part of the p-d interaction together with the strong, static Jahn-Teller effect may lead to a zero-magnetic field splitting and significant modifications of the spin splittings for the valence band. The effect reaches a maximum when all Jahn-Teller distortions are oriented along one of the [100]-type crystallographic directions.
Źródło:
Acta Physica Polonica A; 1991, 80, 2; 295-297
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Dependent Interaction of a Band Electron with Paramagnetic Impurities
Autorzy:
Blinowski, J.
Kacman, P.
Powiązania:
https://bibliotekanauki.pl/articles/1879507.pdf
Data publikacji:
1991-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.-m
71.70.-d
Opis:
A band electron interacting with N electrons in a d-shell of a paramagnetic impurity in zinc-blende type semiconductors was considered. The hybridization of band and d-states in the crystal field and the nonorthogonality mechanisms of interaction were examined in addition to the standard direct exchange. The Heisenberg-type form was derived for the interaction between a Γ$\text{}_{8}$-electron and an impurity with a half-filled d-shell. The domination of the hybridization mechanism explains the observed sign of the effective exchange constant for Γ$\text{}_{8}$ electrons in diluted magnetic semiconductors (DMS) and the difference in magnitude of this constant for Mn$\text{}^{2+}$ and Fe$\text{}^{3+}$ ions in HgSe.
Źródło:
Acta Physica Polonica A; 1991, 79, 1; 145-148
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Ferromagnetic p-d Exchange in Diluted Magnetic Semiconductors
Autorzy:
Blinowski, J.
Dietl, T.
Kacman, P.
Powiązania:
https://bibliotekanauki.pl/articles/1921558.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.-m
71.70.-d
Opis:
The antiferromagnetic type of the interaction between the Γ$\text{}_{8}$-band electrons and the Mn$\text{}^{2+}$ ions in A$\text{}^{II}$B$\text{}^{IV}$ diluted magnetic semiconductors has been explained by invoking the p-d hybridization mechanism. In this paper it is shown that for particular electronic configurations of the magnetic ions in diluted magnetic semiconductors the p-d hybridization can lead to a ferromagnetic interaction between the valence-band electrons and the localized spins. This happens when all the one-electron d-orbitals which hybridize with p-band states are empty (e.g., as in Sc$\text{}^{2+}$ and Ti$\text{}^{2+}$ ions). The appropriate p-d Hamiltonian is derived and the ferromagnetic exchange constants are evaluated.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 641-644
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat Capacity Studies of $NdNi_4Si$ Compound
Autorzy:
Falkowski, M.
Reiffers, M.
Zapotoková, M.
Kowalczyk, A.
Toliński, T.
Gažo, E.
Powiązania:
https://bibliotekanauki.pl/articles/1810401.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
65.40.De
65.40.gd
71.20.Eh
71.70.-d
Opis:
The study of the heat capacity of the intermetallic compound $NdNi_{4}Si$ including the effect of the magnetic field is reported. This compound crystallizes in the hexagonal $CaCu_5$-type structure, space group P6/mmm. $NdNi_{4}Si$ is ferromagnetic with $T_C$ = 8 K and the saturation magnetic moment of 1.5 $μ_{B}$/f.u. at 4.2 K (in H = 9 T). The heat capacity was analyzed considering the electronic contribution, the Schottky anomaly, and the lattice contributions in the frames of the Debye model. The scheme of the energy levels created by the crystal electric field split is determined from the Schottky contribution to the specific heat. $NdNi_{4}Si$ was characterized by the electronic heat capacity coefficient γ = 85 mJ/(mol $K^2$) and the Debye temperature $Θp_D$ = 325 K.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 126-128
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Orientation of Trions in Charge-Tunable InAs/GaAs Quantum Dots
Autorzy:
Laurent, S.
Eble, B.
Krebs, O.
Lemaître, A.
Urbaszek, B.
Marie, X.
Amand, T.
Voisin, P.
Powiązania:
https://bibliotekanauki.pl/articles/2038221.pdf
Data publikacji:
2004-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.70.-d
72.25.Fe
73.21.La
78.47.+p
Opis:
We report on optical orientation of excitons and trions (singly charged exciton) in individual charge-tunable self-assembled InAs/GaAs quantum dots. When the number of electrons varies from 0 to 2, the trion photoluminescence under quasi-resonant excitation gets progressively polarized from zero to ≈100%. We discuss this behavior as the efficient quenching of exciton spin quantum beats in anisotropic quantum dots due to the trion formation. This result indicates a long hole-spin relaxation time larger than the radiative lifetime, confirmed by time-resolved photoluminescence measurements carried out on a quantum dots ensemble.
Źródło:
Acta Physica Polonica A; 2004, 106, 2; 185-192
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibration and Luminescence Spectroscopic Investigations of the Alkali Rare Earth Double Phosphates M$\text{}_{3}$(RE,Eu)(PO$\text{}_{4}$)$\text{}_{2}$ (M=K, Rb; RE=La, Gd)
Autorzy:
Kloss, M.
Schwarz, L.
Hölsä, J. P. K.
Powiązania:
https://bibliotekanauki.pl/articles/1995573.pdf
Data publikacji:
1999-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.50.-f
61.66.Fn
63.20.-e
71.20.Dg
71.20.Eh
71.70.-d
78.30.-j
78.55.-m
Opis:
The room temperature IR- and Raman spectra of the different M$\text{}_{3}$RE(PO$\text{}_{4}$)$\text{}_{2}$ (M = K, Rb; RE = La, Eu, Gd) double phosphates were analysed and used to interpret the vibronic side band structure in the photoluminescence spectra. The intraconfigurational 4f-4f electronic transitions in the photoluminescence spectra of the Eu$\text{}^{3+}$ doped M$\text{}_{3}$RE(PO$\text{}_{4}$)$\text{}_{2}$ were analysed in detail. The crystal field fine structure of the $\text{}^{5}$D$\text{}_{0}$ → $\text{}^{7}$F$\text{}_{J}$ (J=0-4) transitions was analysed accounting for the information on the crystal structure. The effect of the temperature as well as the alkali host cation was evaluated. Finally, a preliminary crystal field energy level scheme for the $\text{}^{7}$F$\text{}_{J}$ (J=0-4) ground term was deduced from the analysis of the photo-luminescence as well as IR- and Raman spectra.
Źródło:
Acta Physica Polonica A; 1999, 95, 3; 343-349
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Mixed Valence State of $Sm_{1-x}B_{6}$ and $Sm_{1-x}La_{x}B_{6}$ by XANES
Autorzy:
Gabáni, S.
Flachbart, K.
Bednarčík, J.
Welter, E.
Filipov, V.
Shitsevalova, N.
Powiązania:
https://bibliotekanauki.pl/articles/1371509.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.Dm
71.28.+d
71.27.+a
Opis:
We investigated the valence states of samarium ions in Sm deficient $Sm_{1-x}B_{6}$ (x=0.03, 0.05, 0.08, 0.1 and 0.2) sintered samples, in single crystalline solid solutions $Sm_{1-x}La_{x}B_{6}$ (x=0.16, 0.28, 0.4, 0.55 and 0.7) as well as in a $SmB_{6}$ single crystal by X-ray absorption near edge structure (XANES) between 4.2 and 300 K. It was shown that the mixed valence state $v_{Sm}$ of Sm-ions ($v_{Sm}$ ≈ 2.51 for $SmB_{6}$ at 4.2 K) in deficient samples is changed but maintained up to a concentration of 20% of vacancies and up to a concentration of 70% in samples doped with trivalent La-ions, and that in both cases it increases with temperature. On the other hand, the value of $v_{Sm}$ increases with increasing vacancy level, whereas it decreases with increasing $La^{3+}$ substitution. The obtained dependences of Sm-valence in $SmB_{6}$ on vacancy as well as on $La^{3+}$ ion concentration are in good agreement with susceptibility measurements and exact numerical calculation of the spinless Falicov-Kimball model in two dimensions.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 338-339
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-Ray Resonant Magnetic Scattering: Application to Thin Films and Multilayers
Autorzy:
Raoux, D.
Jaouen, N.
Tonnerre, J. M.
Bontempi, E.
Powiązania:
https://bibliotekanauki.pl/articles/2014370.pdf
Data publikacji:
2000-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.28.+d
78.70.Ck
71.27.+a
Opis:
This paper reports on the use of a new technique to investigate the magnetic properties of thin films, multilayers and artificial structures, the X-ray resonant magnetic scattering at small values of the scattering vector. It can be used either by registering the reflectivity pattern or in a diffraction mode. In comparison with magneto-optical Kerr effect or neutron scattering, it offers an atomic selectivity due to the resonant excitation of a core electron, and even an electronic shell one. Examples are presented mainly in the soft X-range allowing to probe the 3d band of transition metals. They demonstrate the promising possibilities of the method to measure the magnetic moments carried by each of the atomic components in complex systems, as well as their distribution through thin layers, with an atomic resolution.
Źródło:
Acta Physica Polonica A; 2000, 98, 5; 483-494
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D Angular Correlation of Annihilation Radiation: Current Trends and Future Possibilities
Autorzy:
West, R. N.
Powiązania:
https://bibliotekanauki.pl/articles/1933550.pdf
Data publikacji:
1995-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.28.+d
71.25.Ηc
78.70.Bj
Opis:
Recent improvements in two-dimensional angular correlation measurement and analysis techniques have greatly increased the power of the method to image the Fermi surfaces of electronically complex systems. That, and the further and dramatic improvement that must result when the present radioisotope positron sources are replaced by intense monoenergetic positron beams are discussed and illustrated.
Źródło:
Acta Physica Polonica A; 1995, 88, 1; 249-256
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact Ionization Driven Chaotic Photoluminescence Oscillations in Ga$\text{}_{0.47}$In$\text{}_{0.53}$As
Autorzy:
Godlewski, M.
Fronc, K.
Gajewska, M.
Chen, W.M.
Monemar, B.
Powiązania:
https://bibliotekanauki.pl/articles/1888119.pdf
Data publikacji:
1991-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.+z
72.70.+m
76.90.+d
Opis:
A new application of the Optically Detected Cyclotron Resonance (ODCR) is presented. We report impact ionization studies of bound exciton: (BE) and shallow donor related recombination processes in Ga$\text{}_{0.47}$In$\text{}_{0.53}$As. An appearance of chaotic oscillations in photoluminescence (PL) intensity is observed under condition of impact ionization of deeper donors.
Źródło:
Acta Physica Polonica A; 1991, 80, 2; 271-274
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hot Carrier Effects in Optically Detected Cyclotron Resonance Studies of III-V Semiconductors
Autorzy:
Karpińska, K.
Dedulewicz, S.
Godlewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1920978.pdf
Data publikacji:
1992-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.35.+z
72.70.+m
76.90.+d
Opis:
The mechanisms of irregular photoluminescence intensity oscillations, as observed in optically detected cyclotron resonance experiments, are discussed. Two possible scenarios are analyzed, both requiring impact ionization of the center(s) by electric field accelerated free carriers. The first assumes coexistence of dielectric and energy relaxation processes. The second assumes a subsequent impact ionization of two different centers.
Źródło:
Acta Physica Polonica A; 1992, 82, 4; 623-626
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Universal Scaling of Basic Properties of the Heavy-Fermion Superconductors
Autorzy:
Karbowski, J.
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1930572.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Tx
75.30.Mb
71.28.+d
Opis:
We show that the properties of the heavy-electron superconducting state induced by the interorbital kinetic exchange scale with the effective mass renormalization m*/m$\text{}_{0}$ ~ 1/T$\text{}_{K}$. Explicitly, the pairing potential J̃ ~ J(m$\text{}_{0}$/m*)ln$\text{}^{2}$(m$\text{}_{0}$/m*), where J is the magnitude of the bare Kondo coupling; the coherence length ξ ~ T$\text{}_{K}$/T$\text{}_{c}$ where T$\text{}_{c}$ is the transition temperature, whereas the penetration depth λ ~ (m*/m$\text{}_{0}$)$\text{}^{½}$ so that λ/ξ >> 1. We also determine the scaling of magnetic critical fields.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 341-345
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exchange Interaction as a Source of Real Space Pairing in High Temperature Superconductors and Heavy Fermions: a Brief Overview
Autorzy:
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1860823.pdf
Data publikacji:
1994-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.28.+d
75.10.Lp
74.70.Vy
Opis:
We characterize the principal difference between the pairing induced by the kinetic exchange interactions for the Fermi-liquid and spin-liquid phases. In the case of hybridized electrons the Kondo-exchange induced pairing is invoked, whereas for a single narrow-band case kinetic exchange is responsible for the spin singlet pairing. The former interaction is applied to heavy-fermion systems, whereas the latter is employed to the high temperature superconductors. The current situation concerning the applicability of our theoretical models is briefly and critically assessed.
Źródło:
Acta Physica Polonica A; 1994, 85, 1; 39-52
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultramarine, Lazurite and Sodalite Studied by Positron Annihilation and EPR Methods
Autorzy:
Baranowski, A.
Dębowska, M.
Jerie, K.
Jezierski, A.
Sachanbiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933463.pdf
Data publikacji:
1995-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.60.+z
78.70.-g
61.90.+d
76.30.-v
Opis:
Studies of positron annihilation accompanied by EPR technique were undertaken for sodalite and lazurite and their synthetic counterparts (synthetic sodalite and ultramarines). Results of measurements performed by two techniques of positron annihilation spectroscopy (angular correlation of annihilation radiation, ACAR, and positron annihilation lifetime) revealed the undoubted influence of free radicals on positron annihilation mechanism but both inhibition of positronium formation by them and the effect of filling cages ought to be taken into account. The distinct differences between ACAR curves for sodalites, lazurites and ultramarines probably reflect the presence of different radicals in their cages and chemical heterogeneity as well as the disorder in Al, Si-site ordering in case of ultramarines. Comparison of the results of ACAR measurements with the ones of the EPR studies indicates that there is correspondence between them. Similarly to three families of the ACAR curves, different likes of EPR lines were obtained for three groups of samples; sodalites, lazurites and ultramarines. It is possible that the annihilation of positrons takes place mainly with unpaired electrons recorded by the EPR technique.
Źródło:
Acta Physica Polonica A; 1995, 88, 1; 29-41
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Double Reflection of Electron Spin in Semiconductors
Autorzy:
Dargys, A.
Powiązania:
https://bibliotekanauki.pl/articles/1505522.pdf
Data publikacji:
2011-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
72.25.Dc
71.70.Ej
03.65.Fd
Opis:
Reflection of spin-polarized electron from a potential barrier in bulk semiconductor in the presence of spin-orbit interaction is considered. The spin-orbit interaction brings about double electron reflection at oblique incidence of electronic beam onto the barrier. The competition between the Rashba and Dresselhaus spin-orbit mechanisms during double reflection is discussed. The problem was solved within the Clifford algebra framework, which allows one to describe the spin in a real Euclidean $ℰ_3$ space rather than in an abstract Hilbert space.
Źródło:
Acta Physica Polonica A; 2011, 119, 2; 161-163
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Edelstein Effect in the Presence of Impurity Spin-Orbit Scattering
Autorzy:
Maleki Sheikhabadi, A.
Raimondi, R.
Shen, Ka
Powiązania:
https://bibliotekanauki.pl/articles/1032406.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
71.70.Ej
72.20.Dp
85.75.-d
Opis:
In this paper we study the current-induced spin polarization in a two-dimensional electron gas, known also as the Edelstein effect. Compared to previous treatments, we consider both the Rashba and Dresselhaus spin-orbit interaction as well as the spin-orbit interaction from impurity scattering. In evaluating the Kubo formula for the spin polarization response to an applied electric field, we explicitly take into account the side-jump and skew-scattering effects. We show that the inclusion of side-jump and skew-scattering modifies the expression of the current-induced spin polarization.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 135-139
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of Spin-Dependent Mechanical Friction at Atomic Level
Autorzy:
Gzik-Szumiata, M.
Szumiata, T.
Morozow, D.
Powiązania:
https://bibliotekanauki.pl/articles/1030428.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
62.20.Qp
46.55.+d
75.30.Et
71.70.Gm
75.50.Bb
75.45.+j
Opis:
In this work a simple 2D model of pseudostatic friction at atomic level has been prepared, in the frame of which both Lennard-Jones potential and spin-dependent term of exchange interaction has been included. As an example, it has been demonstrated, that for iron both average lateral and normal forces between atoms of "base" and "slider" in the tribological node are altered through the change of relative direction of spins, by over a dozen of percent, when the interatomic distance is comparable to the lattice constant. Spin-dependent correction of atomic-level friction coefficient has been estimated.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 713-715
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-27 z 27

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies