|About this Abstract
||Materials Science & Technology 2019
||Late News Poster Session
||P2-22: Use of Resonant Ultrasound Spectroscopy to Explore the Temperature Dependent Elasticity of Thermoelectric SnSe
||Ashoka Karunarathne, Gautam Priyadarshan, Joseph Gladden
|On-Site Speaker (Planned)
Resonant ultrasound spectroscopy is a nondestructive acoustical technique to make precise measurements of the elastic constants of crystalline solids with various crystal symmetries. Thermoelectric SnSe, which shows a high efficiency of thermoelectric action at T > 900K, has an orthorhombic Pnma crystal phase at low temperatures and exhibits a phase transition to Cmcm phase at ~ 810 K. Here we present the temperature dependence of the elastic constants and derived elastic moduli of single crystalline SnSe at elevated temperatures (295 – 773 K). Elastic constants show up to a ~70 % reduction with increasing temperature, except for C33. The observed increase of C33 with temperature is explained by the bond strengthening along c-axis of the crystal. We have observed the occurrence of the phase transition between 793 – 813 K by analyzing the temperature dependent normal mode frequency trends.