Article
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.ru
Kalashnikov I.Y. Candidate of Engineering, kalash2605@mail.ru
Bibliographic description
Section Scientific Research
UDK 537.226.1:537.311.322
DOI
Article type
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.
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Full articleStudying 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