2022/07/10 by L N Lukyanova, Lukyanova, L N, Yu. A. Boĭkov +9
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Phase-change materials and chalcogenides #Photorefractive and Nonlinear Optics #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2207.04477
openalex publication_date 2022/07/10 · openalex created_date 2022/07/13 · openalex updated_date 2026/07/28
The temperature dependences of the total, crystal lattice and electronic thermal conductivities were investigated in films of topological insulators p-Bi0.5Sb1.5Te3 and p-Bi2Te3 formed by discrete and thermal evaporation methods. The largest decrease in the lattice thermal conductivity owing to the scattering of long-wavelength phonons on the grain interfaces was observed in the films of solid solutions p-Bi0.5Sb1.5Te3 deposited by discrete evaporation on the amorphous substrates of polyimide without thermal treatment. It is shown that in the p-Bi0.5Sb1.5Te3 films with low thermal conductivity the energy dependence of the relaxation time is enhanced, which is specific for the topological insulators. The electronic thermal conductivity was determined taking into account the effective scattering parameter in the relaxation time approximation versus energy in the Lorentz number calculations. The observed increase of the electronic thermal conductivity within the temperature range of 40 - 80 K is related to the weakening of the electrical conductivity temperature dependence and is determined by the increase in the effective scattering parameter at low temperatures due to the effect of scattering on the point antisite and impurity defects. A correlation was established between the thermal conductivity and features of the morphology of the interlayer surface (0001) in the studied films.