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Wyszukujesz frazę "85.75.-d" wg kryterium: Temat


Wyświetlanie 1-47 z 47
Tytuł:
Electron Mediated Mn-Mn Interaction in Quantum Dots
Autorzy:
Bak, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1428517.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.75.-c
75.85.+t
85.75.-d
Opis:
We present a theoretical study of magnetic interaction in quantum dots with magnetic $Mn^{2+}$ in dot impurities. We show that gate voltage applied to the quantum dot shifts the centers of electron clouds. Exact formulae for the perturbed spin density allow us to derive expression for the change of the strength of the sp-d coupling. Estimations show that sp-d exchange integral is very sensitive to the gate voltage variations. Exact formulae for the change of the effective exchange integrals are derived. As the spin coded qubits are elements of the RAM memory, a part of the energy stored in magnetic coupling will be dissipated when information is written or erased. We estimate this energy and find it sufficiently large to destroy quantum coherence during quantum computing. Finally, we discuss the interdot spin coupling and show the effect of gate voltage operations on the spin intra- and interdot Ruderman-Kittel-Kasuya-Yosida coupling.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1219-1221
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Artykuł
Tytuł:
Carrier Spin Dephasing during Spin-Preserving Tunneling in Coupled Quantum Dots
Autorzy:
Krzykowski, M.
Gawełczyk, M.
Machnikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1185791.pdf
Data publikacji:
2016-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
03.65.Yz
Opis:
In this contribution we study carrier tunneling in a system consisting of a pair of coupled quantum dots. We predict the presence of a spin dephasing channel in such a system, which is associated with a "welcher-weg" type of decoherence process occurring during carrier tunneling. In our model such a process is caused by a mismatch of g-factor values in two quantum dots in the presence of external magnetic field. This leads to a mismatch in spin Zeeman splitting between the dots and, in consequence, to the distinguishability of phonons emitted during the tunneling of carriers with opposite spins. Thus we demonstrate a process of spin dephasing without any direct spin-environment coupling present in the model.
Źródło:
Acta Physica Polonica A; 2016, 130, 5; 1165-1168
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accuracy of Effective Mass Equation for a Single and Double Cylindrical Quantum Dot
Autorzy:
Mielnik-Pyszczorski, A.
Gawarecki, K.
Machnikowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1033130.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
03.65.Yz
Opis:
In this contribution we study the accuracy of various forms of electron effective mass equation in reproducing spectral and spin-related features of quantum dot systems. We compare the results of the standard 8 band k·p model to those obtained from effective mass equations obtained by perturbative elimination procedures in various approximtions for a cylindrical quantum dot or a system of two such dots. We calculate the splitting of electronic shells, the electron g-factor and spin-orbit induced spin mixing and show that for a cylindrical dot the g-factor is reproduced very exactly, while for the two other quantities the effective mass equation is much less accurate.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 376-379
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bychkov-Rashba Effect and g-Factor Tuning in Modulation Doped SiGe Quantum Wells
Autorzy:
Malissa, H.
Jantsch, W.
Mühlberger, M.
Schäffler, F.
Wilamowski, Z.
Draxler, M.
Bauer, P.
Powiązania:
https://bibliotekanauki.pl/articles/2038126.pdf
Data publikacji:
2004-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.Fg
85.75.-d
Opis:
We investigate the spin resonance of electrons in one-sided modulation doped Si$\text{}_{1-x}$Ge$\text{}_{x}$ (x=0-10%)) quantum wells defined by Si$\text{}_{0.75}$Ge$\text{}_{0.25}$ barriers. In such structures, the Bychkov-Rashba effect induces an effective magnetic field in the quantum well layer which causes anisotropy of both the g-factor and the spin coherence time. Evaluation of the Rashba coefficient as a function of x yields a monotonic increase. For x=5% the shift in the resonance field exceeds the ESR linewidth already, demonstrating the possibility to use this effect for g-factor tuning to select individual spins in an ensemble.
Źródło:
Acta Physica Polonica A; 2004, 105, 6; 585-590
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and structural characterization of NiXSb (X = Mn, Cr) Heusler ribbon
Autorzy:
Ryba, T.
Vargova, Z.
Ilkovic, S.
Reiffers, M.
Kravcak, J.
Gyepes, R.
Varga, R.
Powiązania:
https://bibliotekanauki.pl/articles/1050967.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.47.Np
75.30.Gw
85.75.-d
Opis:
Half-Heusler alloys with composition NiMnSb and NiCrSb have been prepared by rapid-quenching method. NiMnSb half-Heusler alloy is characterized by single phase C1_{b} with polycrystalline structure while crystalline structure of NiCrSb shows multiphase system. Magnetic measurements indicated high anisotropy and easy magnetization direction in the parallel direction with respect to ribbon axis for NiMnSb alloy while paramagnetic behavior appears for NiCrSb alloy down to 50 K.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 857-859
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverse Edelstein Effect: an Heuristic Derivation
Autorzy:
Raimondi, R.
Shen, Ka
Vignale, G.
Powiązania:
https://bibliotekanauki.pl/articles/1386587.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Dc
75.70.Tj
85.75.-d
Opis:
We provide a heuristic derivation of the "Inverse Edelstein Effect" (IEE), in which a non-equilibrium spin accumulation in the plane of a two-dimensional (interfacial) electron gas drives an electric current perpendicular to its own direction. The drift-diffusion equations that govern the effect are derived and applied to the interpretation of recent experiments. A brief analysis based on the Kubo formula shows that the result is valid also outside the diffusive regime, i.e. when spin and momentum relaxation become comparable.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 454-456
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Hall and Edelstein Effects in Metallic Films
Autorzy:
Borge, J.
Gorini, C.
Vignale, G.
Raimondi, R.
Powiązania:
https://bibliotekanauki.pl/articles/1386604.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Mk
75.70.Tj
85.75.-d
Opis:
In an insulator-metal-insulator junction, inversion-symmetry breaking at the interfaces between the 3D metallic film and the top and bottom insulating layers may give rise to a sizeable (Rashba-like) spin-orbit interaction. In this paper we study the spin Hall and Edelstein effects produced by such an interface interaction through a quasiclassical approach. We find that the spin Hall conductivity has a finite value even if spin-orbit interaction with impurities in the bulk of the metallic film is neglected and disorder is properly taken into account. This is in sharp contrast with the case of a strictly 2D metallic layer, in which case impurity scattering is known to completely suppress Rashba-like contributions to the spin Hall conductivity. The non-vanishing of the latter has a profound influence on the Edelstein effect, which we show to consist of two terms, the first with the standard form valid in an exactly 2D system, and a second arising from the presence of the third dimension.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 457-459
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Dependent Transport through a Single-Wall Carbon Nanotube Quantum Dot with an S=1 Molecule
Autorzy:
Płomińska, A.
Weymann, I.
Powiązania:
https://bibliotekanauki.pl/articles/1386697.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
75.50.Xx
85.75.-d
Opis:
Transport properties of an S=1 molecule attached to a single-wall carbon nanotube quantum dot, which is coupled to two external ferromagnetic leads, are analyzed in the sequential tunneling regime. The magnetizations of the leads are assumed to form either a parallel or an antiparallel magnetic configuration. The calculations are performed by using the real-time diagrammatic technique in the lowest order perturbation theory with respect to the tunnel coupling. It is shown that the presence of the molecule strongly affects the bias voltage dependence of the current and differential conductance in both magnetic configurations, as well as the resulting tunnel magnetoresistance. Negative (greatly enhanced) tunnel magnetoresistance is found in the case of antiferromagnetic (ferromagnetic) coupling between the nanotube and molecule.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 475-477
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
From Magnetic Nanoparticles to Magnetoresistive Biosensors
Autorzy:
Ennen, I.
Albon, C.
Weddemann, A.
Auge, A.
Hedwig, P.
Wittbracht, F.
Regtmeier, A.
Akemeier, D.
Dreyer, A.
Peter, M.
Jutzi, P.
Mattay, J.
Mitzel, N.
Mill, N.
Hütten, A.
Powiązania:
https://bibliotekanauki.pl/articles/1490090.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.70.-w
85.75.-d
75.75.Fk
64.75.Yz
87.85.fk
Opis:
This paper highlights recent advances in synthesis and magnetotransport properties of magnetic Co nanoparticles. It is shown that magnetic Co nanoparticles self-assembled in nanoparticular monolayers revealing giant magnetoresistance similar to granular systems but with additional features resulting from dipolar interactions between small domains of nanoparticles. A spin-valve with one magnetic Co nanoparticular electrode is employed as a model to demonstrate that individual magnetic moments of Co nanoparticles can be coupled to a magnetic Co layer which in turn offers tailoring of the resulting giant magnetoresistance characteristics. In addition, it is demonstrated that combining a magnetic on-off ratchet with magnetic tunneling junctions integrated in the ratchet introduces a new biosensor concept enabling: (1) simultaneous transporting and separating biomolecules, (2) dynamical biomolecule detection when passing magnetic tunneling junctions in a 1D arrangement. It is projected that this biosensor concept could be applied for viruses as well as for bacteria.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 420-425
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dyakonov--Perel Spin Relaxation Suppressed by an Applied Magnetic Field
Autorzy:
Wilamowski, Z.
Jantsch, W.
Powiązania:
https://bibliotekanauki.pl/articles/2036865.pdf
Data publikacji:
2003-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Rb
73.21.Fg
85.75.-d
Opis:
We observe a strong anisotropy of spin relaxation and a decrease in the spin relaxation rate with increasing electron mobility in contrast to predictions of the classical D'yakonov-Perel spin relaxation model. We show that for high electron mobility the cyclotron motion causes an additional modulation of spin-orbit coupling, leading to an effective suppression of the spin relaxation rate.
Źródło:
Acta Physica Polonica A; 2003, 103, 6; 671-674
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Dependent Tunneling in a Magnetic Field for Junctions Involving Normal and Superconducting CDW Metals
Autorzy:
Ekino, T.
Gabovich, A. M.
Suan Li, Mai
Pękała, M.
Szymczak, H.
Voitenko, A. I.
Powiązania:
https://bibliotekanauki.pl/articles/2046730.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.45.Lr
74.50.+r
85.75.-d
Opis:
The voltage, V, dependences of the differential tunnel conductance G(V) were calculated for two kinds of junctions involving normal and superconducting charge-density-wave metals (CDWMs) in the external magnetic field H. The first is a non-symmetrical junction with a CDWM electrode being biased with respect to a ferromagnet. Calculations show that the paramagnetic splitting occurs between spin-up and spin-down components of G(V), similar to what is observed when a superconducting electrode is used instead of the CDWM one. The second setup is symmetric (CDWM-I-CDWM), where I denotes an insulator. If at least one of the CDWM electrodes is normal and H≠0, G(V) will also be spin-split.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 477-484
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current-Induced Magnetic Dynamics in Asymmetric Ferromagnetic Single-Electron Devices
Autorzy:
Kowalik, M.
Powiązania:
https://bibliotekanauki.pl/articles/1810537.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
73.23.Hk
85.75.-d
Opis:
The theoretical calculations of possible dynamics for a localized magnetic moment of the central electrode in ferromagnetic single-electron devices are presented. The spin-transfer torque from spin current absorbed by the central electrode is calculated. Thereafter, an in-plane component of spin torque is regarded during the integration of the Landau-Lifshitz-Gilbert equation and the time evolution of the localized magnetic moment of the central electrode is obtained. The necessary conditions for switching of the magnetic moment are discussed.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 290-292
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Magnetic Field Effects on Spin Polarization of T-Shaped Double Quantum Dots Coupled to Ferromagnetic Leads
Autorzy:
Wójcik, K.
Weymann, I.
Powiązania:
https://bibliotekanauki.pl/articles/1384834.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.23.Hk
73.63.Kv
85.75.-d
Opis:
We analyze the spin-dependent conductance and spin polarization of a double quantum dot in a T-shape configuration coupled to ferromagnetic leads in the presence of external magnetic field. The calculations are performed with the aid of the numerical renormalization group method. We show that in the antiparallel configuration, finite magnetic field can give rise to the full spin polarization of the current, which can be controlled by tuning the dots' levels. On the other hand, for parallel configuration enhanced spin polarization can be generated by an exchange field due to the presence of ferromagnetic leads and can be also tuned by changing level position or external magnetic field. The magnetic field can be thus used to improve the spin-resolved properties of the system.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 222-224
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Dependent Transient Effects in Electron Transport in the Quantum Dot System
Autorzy:
Parafiniuk, P.
Taranko, R.
Powiązania:
https://bibliotekanauki.pl/articles/1791296.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.-b
73.63.Kv
85.75.-d
Opis:
We study the effects of the Coulomb interaction U between the electrons of opposite spins localized in the quantum dot on the time-dependent electron transport through the quantum dot coupled with two non-magnetic leads. We calculate the transient spin-dependent current generated by a pulsed bias voltage applied across the quantum dot system via the equation of motion method for appropriate correlation functions. The influence of the Coulomb interaction on the quantum coherent oscillations and beats of the current, spin current and current polarization ratio is studied. Our results indicate that the coherent beats in both the total and spin currents observed in the case of vanishing Coulomb interaction are strongly suppressed by non-zero Coulomb interaction. We also show that in the case of the pulsed bias almost fully polarized current occurs in some time windows for non-vanishing Coulomb interaction contrary to almost pure charge or spin current at vanishing U.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 844-846
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current Suppression in Transport Through Triple Quantum Dots Coupled to Ferromagnetic Leads
Autorzy:
Wrześniewski, K.
Weymann, I.
Powiązania:
https://bibliotekanauki.pl/articles/1386617.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.23.-b
73.21.La
85.75.-d
Opis:
We consider transport through triple quantum dot system in a triangular geometry weakly coupled to external ferromagnetic leads. The real-time diagrammatic technique in the lowest order perturbation theory is used to calculate the current and Fano factor in the parallel and antiparallel magnetic configuration of the system as well as the resulting tunnel magnetoresistance (TMR). We focus on the transport regime where the current is suppressed and show that it can lead to negative differential conductance and large super-Poissonian shot noise, which are present in both magnetic configurations. Furthermore, we show that for voltages where the system is trapped in a one-particle dark state the TMR becomes suppressed, while for two-particle blockade, the TMR is much enhanced.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 460-462
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin-Polarized Current in Coulomb Blockade and Kondo Regime
Autorzy:
Ogrodnik, P.
Świrkowicz, R.
Powiązania:
https://bibliotekanauki.pl/articles/2047683.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.23.-b
73.21.La
85.75.-d
Opis:
Spin-polarized electron transport through a single-level quantum dot attached to ferromagnetic and non-magnetic leads is studied with the use of the non-equilibrium Green function technique. Current polarization is investigated in dependence on parameters which characterize the device: the lead's polarization, a position of the dot energy level compared to the Fermi level in electrodes, and the Zeeman splitting of the dot level in an external magnetic field applied to the dot. Calculations were performed in two transport regimes: the Coulomb blockade regime with correlation effects treated within the Hartree-Fock approximation and the Kondo regime with a more rigorous approach to many-body effects at low temperatures.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 295-300
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Limitations in the Tunability of the Spin Resonance of 2D Electrons in Si by an Electric Current
Autorzy:
Wilamowski, Z.
Malissa, H.
Glazov, M.
Jantsch, W.
Powiązania:
https://bibliotekanauki.pl/articles/2047703.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
73.63.Hs
75.75.+a
76.30.-v
Opis:
We analyse the recently observed effect of an in-plane electric current through a Si quantum well on the conduction electron spin resonance. We find that the ratio of resonance shift and current density is independent of temperature and dissipation processes, but the channel current is reduced due to a parallel electric channel in heavily modulation doped samples. The inhomogeneous current distribution results in some broadening of the ESR line width. In high mobility Si/SiGe layers the current induced increase in the electron temperature is considerably larger than the increase in the lattice temperature. The signal amplitude scales with the square of electron mobility.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 375-379
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Magneto-Transport Characterization of (Ga,Mn)(Bi,As) Epitaxial Layers
Autorzy:
Levchenko, K.
Andrearczyk, T.
Domagala, J.
Wosinski, T.
Figielski, T.
Sadowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1195381.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
75.30.Gw
73.50.Jt
85.75.-d
Opis:
High-quality layers of the (Ga,Mn)(Bi,As) quaternary compound semiconductor have been grown by the low-temperature molecular-beam epitaxy technique. An effect of Bi incorporation into the (Ga,Mn)As ferromagnetic semiconductor and the post-growth annealing treatment of the layers have been investigated through examination of their magnetic and magneto-transport properties. Significant enhancement of the planar Hall effect magnitude upon addition of Bi into the layers is interpreted as a result of increased spin-orbit coupling in the (Ga,Mn)(Bi,As) layers.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1121-1124
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Why Ferromagnetic Semiconductors?
Autorzy:
Dietl, T.
Powiązania:
https://bibliotekanauki.pl/articles/2030392.pdf
Data publikacji:
2001-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
72.25.Dc
75.30.Hx
85.75.-d
Opis:
Rapid development of information technologies originates from the exponential increase in the density of information that can be processed, stored, and transferred by the unit area of relevant devices. There is, however, a growing amount of evidences that the progress achieved in this way approaches its limits. Various novel ideas put forward to circumvent barriers ahead are described. Particular attention is paid to those concepts which propose to exploit electron or nuclear spins as the information carriers. Here, ferromagnetic semiconductors of III-V or II-VI compounds containing a sizable concentration of transition metals appear as outstanding spintronic materials.
Źródło:
Acta Physica Polonica A; 2001, 100, Supplement; 139-151
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Resonance Absorption in a 2D Electron Gas
Autorzy:
Ungier, W.
Jantsch, W.
Wilamowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2047694.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
73.63.Hs
75.75.+a
76.30.-v
Opis:
We analyze the power absorption at electron spin resonance excited by the Bychkov-Rashba spin-orbit field in a 2D electron gas. We show that, as long as the absorbed power is dissipated by the usual spin lattice relaxation mechanisms, the resonance line shape is expected to be of pure absorption type, i.e., it can be described by the imaginary part of the dynamic magnetic susceptibility. Therefore, the Dysonian line shape observed in ESR of 2D electron gas cannot result from this type of the resonance signal.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 345-350
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Planar Hall Effect in Ferromagnetic (Ga,Mn)As/GaAs Superlattices
Autorzy:
Wesela, W.
Wosiński, T.
Mąkosa, A.
Figielski, T.
Sadowski, J.
Terki, F.
Charar, S.
Powiązania:
https://bibliotekanauki.pl/articles/2047701.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Jt
75.50.Pp
75.30.Gw
85.75.-d
Opis:
The planar Hall effect was used for investigation of magnetic anisotropy in short period (Ga,Mn)As/GaAs superlattices epitaxially grown on (001) oriented GaAs substrate. The results confirmed the existence of low-temperature magnetocrystalline anisotropy in the superlattices with the easy magnetic axes directed along the two in-plane 〈100〉 directions. Attention is paid to the two-state behaviour of the planar Hall resistance at zero magnetic field that provides its usefulness for applications in non-volatile memory devices.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 369-373
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Conductance of the Quantum Wire
Autorzy:
Dargys, A.
Powiązania:
https://bibliotekanauki.pl/articles/1813319.pdf
Data publikacji:
2008-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.La
73.63.Nm
85.35.Be
85.75.-d
Opis:
Spin transport in a semiconducting quantum wire connected to two spin-unpolarized electron reservoirs is investigated. The spin-orbit interaction is included via the Rashba Hamiltonian which together with the Zeeman Hamiltonian determines spin-filtering properties of the wire. The spin current as a function of the voltage was found to have an oscillatory or growing character.
Źródło:
Acta Physica Polonica A; 2008, 113, 3; 937-942
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Valence Band of Cubic Semiconductors from Viewpoint of Clifford Algebra
Autorzy:
Dargys, A.
Powiązania:
https://bibliotekanauki.pl/articles/1807789.pdf
Data publikacji:
2009-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.-m
72.25.Dc
75.10.Jm
85.75.-d
Opis:
In this paper the properties of semiconductors having cubic symmetry are considered in a real multidimensional Euclidean space within the formalism of multivector Clifford algebra rather than, usually used for this purpose, complex Hilbert space. In particular, it is demonstrated how the valence band energy spectrum and spin properties may be calculated within $Cl_5$ Clifford algebra and SO(5) symmetry group related with it.
Źródło:
Acta Physica Polonica A; 2009, 116, 2; 226-231
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bistability of (Ga,Mn)As Ferromagnetic Nanostructures Due to the Domain Walls Switching
Autorzy:
Andrearczyk, T.
Wosiński, T.
Mąkosa, A.
Figielski, T.
Wróbel, J.
Sadowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1791342.pdf
Data publikacji:
2009-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.50.Jt
75.50.Pp
75.30.Gw
75.60.Ch
85.75.-d
Opis:
We designed and investigated four-arm nanostructures, composed of two perpendicularly crossed stripes, fabricated from ferromagnetic (Ga,Mn)As layer by means of electron-beam lithography patterning and chemical etching. The nanostructures exhibit a bistable resistance behavior resulting from two configurations of magnetic domain walls in the central part of the structures. We demonstrate a possibility of switching between two stable resistance states in zero magnetic field by applying a pulse of either weak magnetic field or electric current through the structure.
Źródło:
Acta Physica Polonica A; 2009, 116, 5; 901-903
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ferromagnetic Resonance Study of Exchange Coupled (Ga,Mn)As/GaAs/(Ga,Mn)As Heterostructures
Autorzy:
Dziatkowski, K.
Ge, Z.
Liu, X.
Furdyna, J. K.
Clerjaud, B.
Twardowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2047381.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Pp
76.50.+g
75.70.Cn
75.30.Et
85.75.-d
Opis:
Ferromagnetic resonance study of the exchange coupled (Ga,Mn)As/ GaAs/(Ga,Mn)As heterostructures is reported. The measurements were performed on the series of samples with varying thicknesses d$\text{}_{GaAs}$ of nonmagnetic GaAs spacer, established d$\text{}_{GaAs}$-dependent extent of weak and strong interlayer exchange coupling, judging on the observation of one or two ferromagnetic resonance modes.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 227-232
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation Effects and Spin Dependent Transport in Carbon Nanostructures
Autorzy:
Lipiński, S.
Krychowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/1201833.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.10.Fk
73.63.Fg
73.63.Kv
85.75.-d
Opis:
The impact of symmetry breaking perturbations on the spin dependent transport through carbon nanotube quantum dots in the Kondo regime is discussed. The proposals of spin filter, spin valve and spin battery are presented.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 190-193
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Investigation of ZnO Nanowires
Autorzy:
Martínez-Criado, G.
Hernández-Vélez, M.
Letard, I.
Cros, A.
Cantarero, A.
Mínguez-Bacho, I.
Susini, J.
Tucoulou, R.
Sans, J.
Sanz, R.
Vázquez, M.
Powiązania:
https://bibliotekanauki.pl/articles/1539044.pdf
Data publikacji:
2010-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
61.10.Ht
78.70.En
81.05.Ea
Opis:
In this study we report the application of synchrotron X-ray fluorescence, photoluminescence and Raman scattering techniques to the analysis of the incorporation of impurities in unintentionally doped ZnO nanowires. Highly ordered one-dimensional ZnO arrays were fabricated by an oxidation process of Zn metal electrodeposited in nanoporous anodic alumina template. X-ray fluorescence data show the contribution of residual elements into the ZnO nanowires growth. A rough analytical quantification of the main light and heavy chemical contents derives impurity concentrations below 1%. The optical efficiency of ZnO nanowires is strongly affected by non-radiative centers up to temperatures as low as 100 K. The photoluminescence was found to be totally dominated by optical transitions associated with the anodic alumina template. Finally, the Raman scattering provides no evidence of local vibrational modes or secondary phases, but it shows the unambiguous signature of the ZnO hexagonal phase.
Źródło:
Acta Physica Polonica A; 2010, 117, 2; 369-373
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:
Spin-Polarized Transport through Quantum Dots in the Cotunneling Regime
Autorzy:
Weymann, I.
Powiązania:
https://bibliotekanauki.pl/articles/1813873.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Mk
73.63.Kv
85.75.-d
73.23.Hk
Opis:
The spin-polarized transport through two-level quantum dots weakly coupled to ferromagnetic leads is considered theoretically in the Coulomb blockade regime. It is assumed that the dot is doubly occupied, so that the current flows due to cotunneling through singlet and triplet states of the dot. It is shown that, by sweeping the bias voltage, one can induce a singlet-triplet transition, which depends on the magnetic configuration of the system and leads to nontrivial bias dependence of both the differential conductance and tunnel magnetoresistance.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 529-532
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport through Single-Wall Carbon Nanotubes Weakly Coupled to External Leads
Autorzy:
Weymann, I.
Krompiewski, S.
Barnaś, J.
Powiązania:
https://bibliotekanauki.pl/articles/1810542.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Mk
73.63.Kv
85.75.-d
73.23.Hk
Opis:
We consider transport properties of single-wall metallic carbon nanotubes weakly coupled to external leads. In particular, we analyze the conductance and shot noise of nanotubes coupled to nonmagnetic leads and show that the shot noise may become super-Poissonian depending on the ground state of the nanotube. In addition, we also show that when the nanotube is coupled to one ferromagnetic and one nonmagnetic lead, it can operate as a gate-controlled spin diode.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 296-298
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:
Unzipped and Defective Nanotubes: Rolling up Graphene and Unrolling Tubes
Autorzy:
Chico, L.
Santos, H.
Ayuela, A.
Jaskólski, W.
Pelc, M.
Brey, L.
Powiązania:
https://bibliotekanauki.pl/articles/1535883.pdf
Data publikacji:
2010-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.U-
73.20.-r
73.63.Fg
85.75.-d
Opis:
The properties of carbon nanotubes can be dramatically altered by the presence of defects. In this work we address the properties of two different kinds of defective nanotubes: junctions of achiral tubes with topological defects and partially unzipped carbon nanotubes. In particular, we begin by focussing on the interface states in carbon nanotube junctions between achiral tubes. We show that their number and energies can be derived by applying the Born-von Karman boundary condition to an interface between armchair- and zigzag-terminated semi-infinite graphene layers. We show that these interface states, which were thought to be due to the presence of topological defects, are in fact related to the graphene zigzag edge states. Secondly, we study partially unzipped carbon nanotubes, which can be considered as the junction of a carbon nanotube and a graphene nanoribbon, which has edge features giving rise to novel properties. Carbon nanoribbons act as transparent contacts for nanotubes and viceversa, yielding a high conductance. At certain energies, nanoribbons behave as valley filters for carbon nanotubes; this holds considering electron-electron interaction effects. Furthermore, the application of a magnetic field turns the system conducting, with a 100% magnetoresistance. These novel structures may open a way for new carbon-based devices.
Źródło:
Acta Physica Polonica A; 2010, 118, 3; 433-441
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lateral Spin Diffusion Probed by Two-Color Hanle-MOKE Technique
Autorzy:
Quast, J.
Astakhov, G.
Ossau, W.
Molenkamp, L.
Heinrich, J.
Höfling, S.
Forchel, A.
Powiązania:
https://bibliotekanauki.pl/articles/1811976.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.25.Dc
72.25.Fe
85.75.-d
72.25.Rb
Opis:
We report on all optical spatially resolved spin diffusion experiments in an unstrained, unbiased n-GaAs layer. Optical pump and probe intensities are varied over a wide range to study the impact of optical disturbance on spin transport. Both quantities have a considerable influence on the measured spin diffusion length and spin lifetime. Furthermore, an effective spin diffusion coefficient was obtained as a function of temperature.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1311-1316
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fano-Kondo Effect of Magnetic Impurity with Side-Coupled Graphene Flake
Autorzy:
Krychowski, D.
Kopiński, J.
Lipiński, S.
Powiązania:
https://bibliotekanauki.pl/articles/1201853.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.22.Pr
72.80.Vp
73.23.-b
72.15.Qm
85.75.-d
Opis:
We examine transport through a spin-1/2 Kondo impurity, patterned between atomic scale electrodes in the presence of side-coupled nanographene flake. Impurity is attached to the edge of the flake, what allows to test the edge states. The Kotliar Ruckenstein slave boson approach is adopted to describe the strongly correlated impurity. We show that transport measurement of Fano-Kondo effect can serve as a spectroscopic probe of spin resolved graphene flake energy levels. The edge moments can be completely suppressed by gate voltage.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 202-203
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Polymer Nanocomposite for Medical Application
Autorzy:
Świętek, M.
Tokarz, W.
Tarasiuk, J.
Wroński, S.
Błażewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/1197651.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
82.35.Np
87.85.-d
87.85.Rs
75.75.-c
87.85.J-
87.85.Lf
Opis:
Magnetic sponges derived from biocompatible and resorbable polymers are promising materials for medical applications. These materials have been utilised extensively in research applications for the capture of biomolecules and cells, the construction of tissue scaffolds and in regenerative medicine. The object of this study was a polymer scaffold made of polycaprolactone (PCL) containing a 10 wt% amount of nanomagnetite, manufactured in a two-step method. The porosity and morphological parameters were characterised with the use of μ-computer-aided tomography and scanning electron microscopy. Furthermore, the magnetic properties were evaluated. The obtained results confirmed high porosity and the appearance of randomly oriented pores. Moreover, evaluations of the magnetic properties, of both the magnetite nanopowder and the prepared magnetic nanocomposite, were performed. The tests verified the ferromagnetic character of the materials under investigation.
Źródło:
Acta Physica Polonica A; 2014, 125, 4; 891-894
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Minor Loops in the Harrison Model
Autorzy:
Chwastek, K.
Szczygłowski, J.
Wilczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1431773.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.60.-d
75.60.Ej
85.70.Ay
Opis:
A novel description of hysteresis phenomenon is presented. The examined description emphasizes the roles of bistability and quantum phenomena as processes responsible for hysteresis loop formation in magnetic materials. Major and symmetric minor hysteresis loops are modelled in chosen soft magnetic materials using the Harrison model. A reasonable agreement between theory and experiment is achieved.
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 941-944
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Link between Magnetic and Dielectric Properties in Magnetite
Autorzy:
Švindrych, Z.
Youssef, A.
Janů, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1534794.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.30.+h
75.60.-d
75.85.+t
Opis:
We have measured temperature dependence of magnetic and dielectric properties in high quality stoichiometric single-crystals of magnetite $(Fe_3O_4)$. At low temperatures, below the Verwey transition, both ac susceptibility and ac permittivity reveal similar relaxation processes. We discuss these effects in connection with domain structure and variable range hopping mechanism of electrical conductivity.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 940-941
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of the $Bi_{0.65}La_{0.35}Fe_{0.5}Sc_{0.5}O_3$ Perovskite
Autorzy:
Fedorchenko, A.
Fertman, E.
Desnenko, V.
Kotlyar, O.
Čižmár, E.
Shvartsman, V.
Lupascu, D.
Salamon, S.
Wende, H.
Salak, A.
Khalyavin, D.
Olekhnovich, N.
Pushkarev, A.
Radyush, Yu.
Feher, A.
Powiązania:
https://bibliotekanauki.pl/articles/1398308.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.85.+t
75.60.Ej
75.60.-d
75.50.Ee
Opis:
Magnetic properties of polycrystalline multiferroic $Bi_{0.65}La_{0.35}Fe_{0.5}Sc_{0.5}O_3$ synthesized under high-pressure (6 GPa) and high-temperature (1500 K) conditions were studied using a SQUID magnetometer technique. The temperature dependent static magnetic moment M was measured in both zero-field-cooled and field-cooled modes over the temperature range of 5-300 K in low magnetic field H=0.02 kOe. The field dependent magnetization M(H) was measured in magnetic fields up to 50 kOe at different temperatures up to 230 K after zero-field cooling procedure. A long-range magnetic ordering of the antiferromagnetic type with a weak ferromagnetic contribution takes place below $T_{N} ≈ 220 K$. Magnetic hysteresis loops taken below $T_{N}$ show a huge coercive field up to $H_{c}$ ≈10 kOe, while the magnetic moment does not saturate up to 50 kOe. A strong effect of magnetic field on the magnetic properties of the compound has been found. Below $T_{N}$ ≈220 K the derivatives of the initial magnetization curves demonstrate the existence of a temperature-dependent anomaly in fields of H=15÷25 kOe. The nature of the anomaly is unknown and requires additional study.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 1069-1071
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Anisotropic Vector Preisach Model for Bulk Materials
Autorzy:
Frydrych, P.
Szewczyk, R.
Nowicki, M.
Charubin, T.
Powiązania:
https://bibliotekanauki.pl/articles/1032677.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.60.-d
75.60.Ch
75.60.Nt
75.30.Gw
85.70.-w
Opis:
In this paper possibility of application two-dimensional vector Preisach model for bulk materials was investigated. Physical magnetization mechanisms in bulk cores and thin ribbons were analyzed. Model is based on collection of the Preisach planes which describe material state in different angles on rotation plane. Presented model exhibits good conformity with experimental data for bulk as well for ribbon shaped cores. Model includes anisotropy and describes not only mean magnetization vector, but also distribution of magnetic moments for different angles.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 618-620
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dependence of Ultrasonic and Magnetic Hyperthermia on the Concentration of Magnetic Nanoparticles
Autorzy:
Kaczmarek, K.
Hornowski, T.
Bielas, R.
Żak, D.
Timko, M.
Józefczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030383.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.75.-c
43.35.Cg
43.35.Wa
87.85.-d
Opis:
Hyperthermia treatment is the heating of tumor tissue up to temperatures between 41°C and 45°C, which trigger several physiological reactions in the body. Hyperthermia within tissue can be applied through various mechanisms. One of them is magnetic hyperthermia which uses superparamagnetic iron oxide nanoparticles (SPIONs) heated by an externally applied magnetic field. SPIONs can also be used as sonosensitizers in ultrasound hyperthermia increasing acoustic wave attenuation. The impact of SPION concentration on thermal effect during ultrasonic and magnetic hyperthermia was investigated in agar-gel phantom with added magnetite nanoparticles. The presence of nanoparticles in the tissue-mimicking phantom increases the thermal losses of ultrasound energy and temperature of the phantom.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 716-718
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wide Frequency Range AC Magnetic Properties of Fe-Based Composite Materials
Autorzy:
Kollár, P.
Birčáková, Z.
Füzer, J.
Füzerová, J.
Bureš, R.
Fáberová, M.
Powiązania:
https://bibliotekanauki.pl/articles/1507025.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Ni
85.70.-w
75.60.-d
75.50.Bb
Opis:
The aim of this work was to analyze the influence of resin content on contribution of the hysteresis, eddy current and anomalous losses to the total losses in the frequency range from DC to 150 kHz. The samples of composite material were prepared in the form of the ring with outer diameter of 25 mm, inner diameter of 17 mm and height approximately 3 mm and in the form of cylinder with diameter of 25 mm and height approximately 3 mm by a compaction of mixture of iron powder ASC100.29 (90 vol.%) and commercial termoset resins. The DC hysteresis losses were obtained by the measurements of DC hysteresis loops and the total power losses in the frequency range 0.4 Hz-150 kHz from AC hysteresis loops, both at maximum induction 0.05, 0.1 and 0.2 T. The magnetic properties of the composite rings were compared with the properties of the material prepared from the powder supported by Höganäs AB Sweden. By analyzing the frequency dependence of total losses of the Fe-based SMC we found out that hysteresis losses contribute to the total losses as a majority component.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 759-761
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AC Magnetic Properties of Vitroperm Based Composite Materials
Autorzy:
Kollár, P.
Hegedüs, L.
Füzer, J.
Bureš, R.
Fáberová, M.
Powiązania:
https://bibliotekanauki.pl/articles/1533956.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Tt
81.05.Ni
85.70.-w
75.60.-d
75.50.Bb
Opis:
The aim of this work was to investigate the influence of resin content on AC magnetic properties of Vitroperm 800-based composite material to extend possibilities for application of this kind of material at higher frequency (up to 100 kHz). The samples of composite material were prepared in the form of the ring with outer diameter of 25 mm, inner diameter of 18 mm and height approximately 3 mm. Powder mixtures were prepared from Vitroperm 800 in partial nanocrystalline state and commercial termoset resins by mechanical mixing. The AC magnetic properties (losses) at maximum induction up to 0.5 T were measured by MATS-2010SA loop tracer in frequency range 1-100 kHz. The specific resistivity of the material was measured by the van der Pauw method. The magnetic properties of the composite rings were compared with the properties of the material prepared from Fe based powder supported by Höganäs. It was found out that the total losses of the Vitroperm-based soft magnetic composite are more than 10 times lower (at 10 kHz) than that for Fe-based one.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 787-789
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of Correlations and Off-Diagonal Terms in Binary Disordered One-Dimensional Systems
Autorzy:
Kosior, A.
Major, J.
Płodzień, M.
Zakrzewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1189984.pdf
Data publikacji:
2015-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
67.85.-d
03.75.-b
73.20.Fz
73.20.Jc
Opis:
We investigate one-dimensional tight binding model in the presence of a correlated binary disorder. The disorder is due to the interaction of particles with heavy immobile other species. Off-diagonal disorder is created by means of a fast periodic modulation of interspecies interaction. The method based on transfer matrix techniques allows us to calculate the energies of extended modes in the correlated binary disorder. We focus on N-mer correlations and regain known results for the case of purely diagonal disorder. For off-diagonal disorder we find resonant energies. We discuss ambiguous properties of those states and compare analytical results with numerical calculations. Separately we describe a special case of the dual random dimer model.
Źródło:
Acta Physica Polonica A; 2015, 128, 6; 1002-1007
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-Rays Response of Diamond Detectors Constructed Using Diamond Layers Produced by Low Power Microwave Chemical Vapor Deposition Reactor
Autorzy:
Kordyasz, A.
Bednarek, A.
Kowalczyk, M.
Tarasiuk, J.
Kulczycka, E.
Teodorczyk, M.
Gajewski, M.
Kordyasz, Ł.
Rowiński, O.
Lamparski, K.
Karwański, Ł.
Lipczewski, T.
Powiązania:
https://bibliotekanauki.pl/articles/1402641.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.75.-d
81.15.Gh
29.40.Vj
07.85.Fv
Opis:
The low power reactor for microwave chemical vapor deposition process is described. The rotating Mo holder of 12 mm diameter and 6 mm height with the diamond substrate was heated by 2.45 GHz microwaves to temperature about 800°C in the range of (1.5-7)% $CH_{4}//H_{2}$ mixture to create plasma at pressure 70 Tr. Stabilization of the holder temperature was performed by optical observation of radiation from the holder followed by adjusting of the magnetron power. Diamond detectors are produced using microwave chemical vapor deposition process grown on single crystal diamond high pressure high temperature Sumimoto substrates, [100] oriented. The response of diamond detectors for X-rays has been measured in the current mode using medical X-rays tube. The linear response of the diamond detector current versus X-ray tube current (dose) is presented.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1555-1559
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoelectric Properties of $0.3Bi_{0.95}Dy_{0.05}FeO_3-0.7Pb(Fe_{2//3}W_{1//3})O_3$ Multiferroic
Autorzy:
Stoch, A.
Stoch, P.
Kulawik, J.
Zieliński, P.
Maurin, J.
Powiązania:
https://bibliotekanauki.pl/articles/1490931.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.85.+t
77.22.-d
77.55.Nv
77.80.-e
77.80.Jk
Opis:
Pb-based complex perovskites with $Fe^{3+}$ like $Pb(Fe_{2//3}W_{1//3})O_3$ were found to be interesting because of their unique properties such as relaxor and magnetoelectric behavior. $Pb(Fe_{2//3}W_{1//3})O_3$ is ferroelectric with ferroelectric Curie temperature $T_{C}$ between 150 and 200 K and at the same time is antiferromagnetic with magnetic Néel temperature about 400 K. $BiFeO_3$ is a well known perovskite compound which exhibits ferroelectric ($T_{C}$ = 1103 K) and antiferromagnetic ($T_{N}$ = 643 K) ordering simultaneously. The polycrystalline sample of $0.3Bi_{0.95}Dy_{0.05}FeO_3-0.7Pb(Fe_{2//3}W_{1//3})O_3$ were synthesized using standard sintering procedure. Magnetization vs. magnetic field (at 4.2 K) curves were measured. Magnetoelectric properties of the sample were obtained.
Źródło:
Acta Physica Polonica A; 2012, 121, 1; 128-130
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD Flow-Control for Hypersonic Flight
Autorzy:
Petit, J.
Geffray, J.
Powiązania:
https://bibliotekanauki.pl/articles/1807963.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.30.Jr
47.40.Ki
47.65.-d
47.85.lb
52.30.Cv
52.75.Fk
Opis:
At the beginning of the seventies, experimental research using short duration supersonic shock driven wind tunnel were conducted and showed the efficiency of Lorentz force action on supersonic (Mach 1.4) dense (1 bar) low magnetic Reynolds number hot (10 000 K) argon flows. When working as a generator, the linear Faraday MHD converter was efficient enough, due to high electrical conductivity (3000 S/m) to create a front shock wave at the intake of the constant cross-section MHD converter. Accelerations up to 5000 m/s were obtained in 10 cm long channels. This suggested the possibility to achieve complete shock wave and turbulent wake cancellation, through MHD bypass concept. Such work gave publications in peer-reviewed journals and presentation in international MHD meetings (French Academy of Sciences 1970, Moscow 1983, Tsukuba 1986, Beijing 1992). The work was conducted both through computational simulations (based on the method of characteristics) and hydraulic simulation experiments. We present the synthesis of such studies through a project of a hypersonic vehicle based on an MHD bypass concept, landing under its own steam, using classical turbojets. Then, at Mach 3 and high altitude, MHD controlled inlets are opened. A wall converter slows down the hypersonic incoming air flow, without excessive heating, feeding a ramjet system. The subsequent electric power provides an additional impulse to the flow in the exhaust section. Cruise Mach number: 12. Local Hall parameter regime produces high voltage that, sent to the leading edges, creates a plasma cushion which prevents too high thermal flux. Lift is provided by wave riding technique. Additional rocket propeller could transform it as a reusable space launcher.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1149-1151
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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