|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Alloys and Compounds for Thermoelectric and Solar Cell Applications VI
||Molecular-dynamics Simulations of Liquid-like Copper Diffusion in Copper Chalcogenides
||Keenan Zhuo, Jing Wang, Jianping Gao, Uzi Landman, Mei-Yin Chou
|On-Site Speaker (Planned)
It was recently discovered that copper chalcogenides Cu2S and Cu2Se are viable candidates for thermoelectric materials with high figure of merit (ZT) values at temperatures around 1,000 K. The possible reason for the high ZT is the low thermal conductivity arising from liquid-like Cu atoms in those phases. In this work, we report first-principles molecular dynamics simulations to study the motion of Cu atoms in different phases of Cu2S (hexagonal and cubic phases with increasing temperature) and the cubic phase of Cu2Se to confirm the liquid nature of Cu atoms. In the hexagonal phase the Cu atoms show a disordered/liquid-like feature with a jump diffusion pattern. We find that the diffusion is faster in the x-y directions than in the z direction. A more isotropic diffusion pattern is found for the high-temperature cubic phase with a much larger diffusion coefficient.
||Planned: Supplemental Proceedings volume