The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
V. A. Kulbachinskii - One of the best experts on this subject based on the ideXlab platform.
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Shubnikov–de Haas Effect and Electrophysical Properties of the Topological Insulator Sb_2 –_xCu_xTe_3
Journal of Experimental and Theoretical Physics, 2019Co-Authors: V. A. Kulbachinskii, D. A. Zinov’ev, N. V. Maslov, V. G. KytinAbstract:The results of the study of the influence of Cu on the Shubnikov–de Haas Effect and the electrical properties of p -Sb_2 –_ x Cu_ x Te_3 single crystals (0 ≤ x ≤ 0.1) are presented. In the framework of the parabolic model of the energy spectrum, the hole concentrations and the Fermi energy in Sb_2 –_ x Cu_ x Te_3 are calculated based on the oscillation frequencies of the magnetoresistance. It is shown that doping by Cu has an acceptor Effect and significantly increases the frequencies of Shubnikov–de Haas oscillations. A plateau is observed in the dependences of the Hall resistance on magnetic field. The dependences of the resistance on temperature obey the power law with the exponent m = 1.2, which is characteristic of scattering on phonons with the contribution of scattering on ionized impurities. Unlike other impurities, the exponent remains almost unchanged when doped by Cu to the maximum concentrations studied.
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Thermoelectric properties, Shubnikov–de Haas Effect and mobility of charge carriers in bismuth antimony tellurides and selenides and nanocomposite based on these materials
Low Temperature Physics, 2017Co-Authors: V. A. Kulbachinskii, R. A. Lunin, A. A. Kudryashov, Vladimir G. Kytin, Aritra BanerjeeAbstract:We describe here the study of the Shubnikov–de Haas Effect and thermoelectric properties of p-(Bi0.5Sb0.5)2Te3 single crystals doped with Ga, n-Bi2–xTlxSe3 and p-Sb2–xTlxTe3. Using Fourier spectra of the oscillations we calculated the mobility of charge carriers and its variation upon doping. We found that Ga has a donor Effect in p-(Bi0.5Sb0.5)2Te3, Tl is an acceptor in n-Bi2–xTlxSe3 and increases the mobility of electrons, while in p-Sb2–xTlxTe3, Tl is a donor and decreases the mobility of holes. We consider the evolution of the defectiveness of crystals that leads to the observed Effects. We also synthesized and investigated nanocomposites of solid solutions Sb2Te3–xSex (0
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Influence of buffer-layer construction and substrate orientation on the electron mobilities in metamorphic In^0.70Al^0.30As/In^0.76Ga^0.24As/In^0.70Al^0.30As structures on GaAs substrates
Semiconductors, 2015Co-Authors: V. A. Kulbachinskii, N. A. Yuzeeva, G. B. Galiev, E. A. Klimov, L. N. Oveshnikov, R. A. Lunin, S. S. Pushkarev, P. P. MaltsevAbstract:The influence of construction of the buffer layer and misorientation of the substrate on the electrical properties of In^0.70Al^0.30As/In^0.76Ga^0.24As/In^0.70Al^0.30As quantum wells on a GaAs substrate is studied. The temperature dependences (in the temperature range of 4.2 K < T < 300 K) and field dependences (in magnetic fields as high as 6 T) of the sample resistances are measured. Anisotropy of the resistances in different crystallographic directions is detected; this anisotropy depends on the substrate orientation and construction of the metamorphic buffer layer. In addition, the Hall Effect and the Shubnikov–de Haas Effect are studied. The Shubnikov–de Haas Effect is used to determine the mobilities of electrons separately in several occupied dimensionally quantized subbands in different crystallographic directions. The calculated anisotropy of mobilities is in agreement with experimental data on the anisotropy of the resistances.
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Influence of buffer-layer construction and substrate orientation on the electron mobilities in metamorphic In0.70Al0.30As/In0.76Ga0.24As/In0.70Al0.30As structures on GaAs substrates
Semiconductors, 2015Co-Authors: V. A. Kulbachinskii, N. A. Yuzeeva, G. B. Galiev, E. A. Klimov, L. N. Oveshnikov, R. A. Lunin, S. S. Pushkarev, P. P. MaltsevAbstract:The influence of construction of the buffer layer and misorientation of the substrate on the electrical properties of In0.70Al0.30As/In0.76Ga0.24As/In0.70Al0.30As quantum wells on a GaAs substrate is studied. The temperature dependences (in the temperature range of 4.2 K < T < 300 K) and field dependences (in magnetic fields as high as 6 T) of the sample resistances are measured. Anisotropy of the resistances in different crystallographic directions is detected; this anisotropy depends on the substrate orientation and construction of the metamorphic buffer layer. In addition, the Hall Effect and the Shubnikov–de Haas Effect are studied. The Shubnikov–de Haas Effect is used to determine the mobilities of electrons separately in several occupied dimensionally quantized subbands in different crystallographic directions. The calculated anisotropy of mobilities is in agreement with experimental data on the anisotropy of the resistances.
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The Shubnikov-De Haas Effect and thermoelectric properties of Tl-doped Sb2Te3 and Bi2Se3
Semiconductors, 2015Co-Authors: V. A. Kulbachinskii, A. A. Kudryashov, Vladimir G. KytinAbstract:The influence of doping with Tl on the Shubnikov-De Haas Effect at T = 4.2 K in magnetic fields up to 38 T in p-Sb2−x Tl x Te3 (x = 0, 0.005, 0.015, and 0.05) and n-Bi2−x Tl x Se3 (x = 0, 0.01, 0.02, 0.04, and 0.06) single crystals is investigated. Extreme cross-sections of the Fermi surface in both materials decrease upon doping with Tl: the hole concentration decreases in Sb2−x Tl x Te3 due to the donor Effect of Tl and the electron concentration in n-Bi2−x Tl x Se3 decreases due to the acceptor Effect of Tl. The temperature dependences of the Seebeck coefficient, electrical conductivity, thermal conductivity, and dimensionless thermoelectric figure of merit in a temperature range of 77–300 K are measured. The thermal conductivity and electrical conductivity decrease upon doping with Tl both in p-Sb2−x Tl x Te3 and in n-Bi2−x Tl x Se3. The Seebeck coefficient increases in all compositions upon an increase in doping over the entire measured temperature range. The thermoelectric figure of merit increases upon doping with Tl.
Frank Szmulowicz - One of the best experts on this subject based on the ideXlab platform.
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Shubnikov–de Haas Effect in InGaSb/InAs superlattices
Journal of Applied Physics, 2017Co-Authors: W. C. Mitchel, Said Elhamri, H. J. Haugan, Gail J. Brown, Shin Mou, Frank SzmulowiczAbstract:Magneto-transport measurements have been made on strain-free In0.25Ga0.75Sb/InAs superlattices grown on GaSb substrates. The superior structural quality of these superlattices compared to older materials in the literature resulted in a much higher resolution of the Shubnikov–de Haas oscillations. Three separate conduction channels were observed. Measurements with the magnetic field in the plane of the sample indicated that the channel with the longer period was due to three dimensional-like conduction within the superlattice while the other two channels showed two dimensional behavior most likely associated with conduction at the surface or interfaces between the superlattice and bulk-like layers. Comparison with multi-carrier analysis indicated that the channel with intermediate period was due to hole conduction while the others were due to electron conduction. Oscillations were observed at temperatures up to 20 K. The concentration of the superlattice channel at low temperature was 5.93 × 1015 cm−3 whil...
R. Laiho - One of the best experts on this subject based on the ideXlab platform.
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Shubnikov-De Haas Effect in n-CdSb:In under pressure
Semiconductor Science and Technology, 2009Co-Authors: R. Laiho, K. G. Lisunov, A.v. Lashkul, Erkki LähderantaAbstract:Magnetoresistance (MR) of single crystals of the group II–V semiconductor n-CdSb doped with In is investigated in magnetic fields B up to 7 T and temperatures T between 1.2 and 2.4 K under hydrostatic pressure p = 0–10 kbar. Shubnikov–de Haas (SdH) oscillations of MR observed up to B ~ 4 T are characterized by a single period, giving evidence for one participating group of conduction band electrons. Pressure dependence of the SdH period and concentration reveal a second group of charge carriers, connected to a resonance impurity band with delocalized states. The SdH amplitude, A, exhibits non-universal behavior attributable to its sensitivity to scattering mechanism at low quantum numbers. The parameters characterizing the non-universality of A(T) and the pressure dependence of the cyclotron Effective mass, mc(p), and of the concentration of conduction electrons, nSdH, are given. The dependences of mc and the Fermi energy on pressure are consistent with Kane-type non-parabolicity of the conduction band.
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Shubnikov-De Haas Effect in (Cd1−x−yZnxMny)3As2 under Pressure
physica status solidi (b), 1996Co-Authors: R. Laiho, K. G. Lisunov, M. L. Shubnikov, V. N. Stamov, V. S. ZakhvalinskiiAbstract:We have investigated the Shubnikov-De Haas Effect in single crystals of the group II-V diluted magnetic semiconductors (Cd1−x−yZnxMny)AS2(x + y = 0.3, y = 0.06 and 0.08) at temperatures T = 4.2 to 16 K and magnetic fields B = 0 to 6.5 T under hydrostatic pressure p up to 14 kbar. Values of the cyclotron mass mc, the Effective g-factor g*, and the Dingle temperature TD have been determined. In both specimens a linear field dependence mc(B) = m + αB is observed, where m is independent of B but increases with pressure and where a does not depend on p and B. Additionally, pressure dependencies of g*, TD and the Hall mobility μR are observed. The dependence of m and g*, on p is interpreted within the three-band Kane model. The decrease of μR and TD with increasing pressure is consistent with an increase of m.
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Shubnikov-De Haas Effect in (Cd1-x-yZnxMny)3As2 far from the zero-gap state
Journal of Physics and Chemistry of Solids, 1996Co-Authors: R. Laiho, K. G. Lisunov, V. N. Stamov, V.s. ZahvalinskiiAbstract:Abstract The Shubnikov-De Haas Effect in the type II 3 V 2 diluted magnetic semiconductor alloy ( Cd 1− x − y Zn x Mn y ) 3 As 2 was investigated in the region of 0⩽ y ⩽0.08, x + y = 0.3. Single period oscillations of the conductivity were observed in the temperature interval of 4.2–31 K and magnetic fields up to 11 T. In one of the samples ( y = 0.02) a well-resolved spin-splitting was seen. Values of the cyclotron Effective mass and the g -factor were determined. A strong dependence of the cyclotron mass on the magnetic field was observed in crystals with a high Mn concentration.
A. S. Molev - One of the best experts on this subject based on the ideXlab platform.
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Transverse Shubnikov–de Haas Effect and the manifestation of quantum diffraction
International Journal of Modern Physics B, 2020Co-Authors: Yu. A. Berezhnoy, A. S. MolevAbstract:A quantum diffraction interpretation of the transverse Shubnikov–de Haas Effect is presented. Within the framework of the conventional theory of this Effect, we show that the matrix element for the...
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Transverse Shubnikov–de Haas Effect and the manifestation of quantum diffraction
International Journal of Modern Physics B, 2020Co-Authors: Yu. A. Berezhnoy, A. S. MolevAbstract:A quantum diffraction interpretation of the transverse Shubnikov–de Haas Effect is presented. Within the framework of the conventional theory of this Effect, we show that the matrix element for the electron transition from an initial state to a final state used in calculating the transverse electrical conductivity can be represented as a diffraction-type amplitude distribution. The squared modulus of this matrix element under certain conditions exhibits the Fraunhofer diffraction pattern. It is shown that the oscillating part of the transverse conductivity has the same form as the amplitude for Fraunhofer diffraction by an annular aperture.
Luis Balicas - One of the best experts on this subject based on the ideXlab platform.
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Shubnikov-De Haas Effect in the metallic state of Na0.3CoO2.
Physical review letters, 2006Co-Authors: Luis Balicas, James Analytis, K. Storr, Henny W. Zandbergen, Y. Xin, Nigel Hussey, Fangcheng Chou, Patrick A. LeeAbstract:Shubnikov–de Haas oscillations for two well-defined frequencies, corresponding, respectively, to areas of 0.8 and 1.36% of the first Brillouin zone, were observed in single crystals of Na0.3CoO2. The existence of Na superstructures in Na0.3CoO2, coupled with this observation, suggests the possibility that the periods are due to the reconstruction of the large Fermi surface around the ? point. An alternative interpretation in terms of the long sought-after ?g? pockets is also considered but found to be incompatible with existing specific heat data.
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Shubnikov-De Haas Effect and Yamaji oscillations in the antiferromagnetically ordered organic superconductor k-(BETS)2FeBr4: A Fermiology study
Solid State Communications, 2000Co-Authors: Luis Balicas, James S. Brooks, Kevin Storr, David Graf, Shinia Uji, H. Shinagawa, E. Ojima, Hideki Fujiwara, Hayao Kobayashi, Akiko KobayashiAbstract:Shubnikov-De Haas Effect (SdH) Effect and angular dependent magnetoresistance oscillations (AMRO) were observed in the organic superconductor: $\kappa$-(BETS)$_2$FeBr$_4$. In contrast to its isostructural compound $\kappa-(BETS)$_2$FeCl$_4$, SdH oscillations, for fields perpendicular to the conducting planes, reveal three Fermi Surface (FS) closed orbits $\alpha$, $\beta$, and $\gamma$ whose cross sectional areas are 19.8 %, 99.9 %, and 2.4 % of the first Brillouin zone, respectively. The conduction electron Effective masses were found to be: $\mu_{\alpha} = (4.7 \pm 0.2)$ m$_e$, $\mu_{\beta} = (8.0 \pm 1.0)$ m$_e$, and $\mu_{\gamma} = (2.0 \pm 0.2)$ m$_e$. The observation of a $\gamma$ orbit is not expected from band structure calculations, $\mu_{\beta}$ is among the heaviest masses ever reported for an organic conductor. The observed Yamaji-like AMRO indicates a 2-D closed FS, warped along the $k_z$ direction.