| Article |
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| Article name |
Studying Anisotropy of Plasma Resonance in Solid Solutions of Bismuth Telluride and Antimony Telluride in the Infrared Spectrum at Temperatures Ranging from 78 to 293 K |
| Authors |
Gilfanov A.K. Research Associate artem_gilfanov@mail.ruKalashnikov I.Y.Candidate of Engineering kalash2605@mail.ru |
| Bibliographic description |
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| Section |
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| DOI |
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| UDK |
537.226.1:537.311.322 |
| Article type |
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| Annotation |
The article investigates reflection spectra of polarized infrared radiation from
(Bi2−xSbx)Te3 (0 < x < 1) solid solution crystals in the temperature range from 78 to 293 K, in the area of free carriers plasma oscillations excitation. It finds that with the increasing
amount of Sb2Te3 in solid solutions composition from 0 to 50 percent the value of anisotropy
of plasma frequencies and magnetic susceptibility varies only slightly. This suggests that in
given crystals at the temperature of 293 K near the chemical potential level there are no
significant changes in the composition of groups of free carriers. To describe the observed
anisotropy of the plasma frequencies it is necessary to take into consideration the impact
of heavy holes in the valence band. It is also confirmed by the results of the study of the
temperature dependence of plasma reflection spectra that reveal regularities similar to the
anomalous temperature variations of the Hall coefficient. It shows that to describe the decrease
in plasma frequencies observed with the increase in temperatures, the enlargement of effective
mass of charge carriers according to the expression m∗ ∼ T 0,17 is insufficient. This expression
was obtained by interpreting the results of the study of temperature dependence of some
kinetic coefficients. The empirical Moss rule ε2
∞Eg = const was used to estimate the rate of
the thermal band gap decrease dEg/dT = −1, 6 ·10−4 eV/K in a crystal containing 25 percent
of Sb2Te3. |
| Key words |
reflection spectrum, anisotropy of the reflection coefficient, band structure,
bismuth tel-luride, antimony telluride. |
| Article information |
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| References |
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| Full article | Studying Anisotropy of Plasma Resonance in Solid Solutions of Bismuth Telluride and Antimony Telluride in the Infrared Spectrum at Temperatures Ranging from 78 to 293 K |
