no code implementations • 20 Jan 2021 • Jiang Cao, Đorđe Dangić, José D. Querales-Flores, Stephen Fahy, Ivana Savić
IV-VI materials are some of the most efficient bulk thermoelectric materials due to their proximity to soft-mode phase transitions, which leads to low lattice thermal conductivity.
Materials Science Computational Physics
no code implementations • 15 Dec 2020 • Đorđe Dangić, Olle Hellman, Stephen Fahy, Ivana Savić
However, the $\kappa$ of GeTe increases at the ferroelectric phase transition near $700$ K. Using first-principles calculations with the temperature dependent effective potential method, we show that this rise in $\kappa$ is the consequence of negative thermal expansion in the rhombohedral phase and increase in the phonon lifetimes in the high-symmetry phase.
Materials Science