Central peak and acoustic anomalies of the relaxor ferroelectric lead magnesium niobate-lead titanate single crystal studied by the micro-Brillouin scattering

Quasielastic central peak and acoustic anomalies in a [001] lead magnesium niobate-lead titanate single crystal have been investigated by the high-resolution micro-Brillouin scattering. Two acoustic anomalies were observed at temperatures, TC-T similar to 415 K and TT-R similar to 348 K. The damping showed a significant dispersion at T similar to 550 K, associated with the enhanced dynamics of local strain fields created by the polar microregions. The temperature evolution of the quasielastic central peak exhibited anomalies in the overall intensity and relaxation time that were associated with the line shape interferences of the central peak and the acoustic mode.