Abstract

Bulk extruded (including nanostructured) samples of Bi₈₅Sb₁₅ solid solutions consisting of particles with average sizes of 0.5 × 10⁵, 380, 30, and 15 nm were obtained and their electrical conductivity ($\sigma$), thermo-e.m.f. ($\alpha$), Hall (R_H), and thermal conductivity ($\chi$) coefficients in the temperature range ∼77–300 K and magnetic field strength (H) up to ∼74 × 10⁴ A/m have been investigated. With decreasing powder sizes in the samples an increase in $\sigma$ and a decrease in phonon thermal conductivity (${\chi }_l^{}$) and $\alpha ,$ R_H are observed; the dependences of these parameters of the samples on the size of the powders satisfactorily correlate in the studied temperature range. As the size of the crystals decreases, the concentration of the boundaries increases, this leads to increase of electron concentration in the samples. Effect of H on the electrical and thermal properties for annealed samples of Bi₈₅Sb₁₅ solid solutions was stronger than for the samples that have not undergone annealing.

摘要

获得了由平均尺寸为 0.5 × 10 ⁵、380、30 和 15 nm的颗粒组成的 Bi ₈₅ Sb ₁₅固溶体的块状挤压（包括纳米结构）样品及其电导率（$\sigma$), 热电动势 ($\alpha$)、霍尔 ( R _H ) 和热导率 ($\chi$) 系数在 ~77–300 K 的温度范围内和磁场强度 ( H ) 高达 ~74 × 10 ⁴  A/m 已被研究。随着样品中粉末尺寸的减小，$\sigma$ 和声子热导率的降低（${\chi }_{升}^{}$) 和 $\alpha ,$ 观察到R _H；样品的这些参数对粉末尺寸的依赖性在所研究的温度范围内具有令人满意的相关性。随着晶体尺寸的减小，边界的浓度增加，这导致样品中电子浓度的增加。的效果ħ对铋的退火的样品的电特性和热特性₈₅的Sb _15个的固溶体是比没有经历退火样品更强。