The Results of Thermal Expansion Investigation for Effective Thermoelectric Materials

Abstract

The thermal expansion of effective thermoelectric materials in the temperature range of 200-1200 K has been studied using quartz dilatometers. In present work the method and mathematical model for calculation of thermal linear expansion coefficients (TLEC) of thermoelectric materials were chosen and substantiated. As a result of the study, it was experimentally established that the TLEC of low temperature thermoelectric materials Bi 2 Te 2.8 Se 0.2 and Bi 0.5 Sb 1.5 Te 3 are 14.8510-6 K-1 and 14.9810-6 K-1 in the temperature range of 200-400 K respectively. Research of middle temperature materials was performed. It was found that the TLEC of Bi 2 Te 2.4 Se 0.6 and Bi 0.4 Sb 1.6 Te 3 weakly change in the working temperature range from 380 to 600 K and is in the range of (13.93-14.33)10-6 K-1. Values of TLEC for PbTe is 23.0710-6 K-1, value of TLEC of GeTe is 24.4710-6 K-1 respectively. TLEC for high temperature nanostructural material Si 0.8 Ge 0.2 is equal to 4.6810-6 K-1 in the temperature range 300-1200 K.