Abstract
Thermomechanical characterization is important to material evaluation and device design in the development of thermoelectric technology.
In this study, we utilize the resonant ultrasound spectroscopy (RUS) technique to examine the elastic behavior of a cast LAST
(Pb–Sb–Ag–Te) material with a composition of Ag0.86Pb19Sb1.0Te20 between room temperature and 823 K. The temperature-dependent
Young’s modulus exhibits a monotonically decreasing trend with increasing temperature. However, an abnormal slope change in the
Young’s modulus–temperature curve around 500 K is observed. In addition, hysteresis between heating and cooling data in the temperature
range of 450–550 K is observed, which appears to be dependent on the heating/cooling rate during the RUS experiments such that
the hysteresis disappears when the heating/cooling rate was decreased from 5 to 2 K min–1. In this study we propose an order–disorder
transition model for the anomalous temperature-dependent Young’s modulus behavior observed in this study.
