Dynamic crystallography reveals spontaneous anisotropy in cubic GeTe.

ABSTRACT: Cubic energy materials such as thermoelectrics or hybrid perovskite materials are often understood to be highly disordered^1,2. In GeTe and related IV-VI compounds, this is thought to provide the low thermal conductivities needed for thermoelectric applications¹. Since conventional crystallography cannot distinguish between static disorder and atomic motions, we develop the energy-resolved variable-shutter pair distribution function technique. This collects structural snapshots with varying exposure times, on timescales relevant for atomic motions. In disagreement with previous interpretations^3-5, we find the time-averaged structure of GeTe to be crystalline at all temperatures, but with anisotropic anharmonic dynamics at higher temperatures that resemble st

SUBMITTER: Kimber SAJ 

PROVIDER: S-EPMC9981458 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature