Acoustic Anomalies and the Critical Slowing-Down Behavior of MAPbCl₃ Single Crystals Studied by Brillouin Light Scattering.

ABSTRACT: Inelastic light scattering spectra of organic-inorganic halide perovskite MAPbCl₃ single crystals were investigated by using Brillouin spectroscopy. Sound velocities and acoustic absorption coefficients of longitudinal and transverse acoustic modes propagating along the cubic [100] direction were determined in a wide temperature range. The sound velocities exhibited softening upon cooling in the cubic phase, which was accompanied by the increasing acoustic damping. The obtained relaxation time showed a critical slowing-down behavior, revealing the order-disorder nature of the phase transition, which is consistent with the growth of strong central peaks upon cooling toward the phase transition point. The temperature dependences of the two elastic constants C₁₁ a

SUBMITTER: Lee JW 

PROVIDER: S-EPMC9145713 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature