Brillouin spectroscopy study of the stress-induced ferroelectric order in lead-free relaxor 0.93(Na1/2Bi1/2)TiO3-0.07BaTiO3 ceramics

In this study, in situ stress-dependent Raman and Brillouin spectroscopy has been performed on polycrystalline 0.93(Na1/2Bi1/2)TiO3-0.07BaTiO(3) (NBT-7BT). Brillouin scattering revealed stress-dependent changes in the elastic properties around the onset stress as well as the appearance of a transversal acoustic wave mode at elevated stress levels, which is understood to be due to the formation of long-range order. These data were compared with additional Raman scattering measurements, ex situ x-ray diffraction, and macroscopic stress-strain behavior, which revealed analogous changes in the apparent crystallographic structure and ferroelectric order in the vicinity of the onset and coercive stresses. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, in situ stress-dependent Raman and Brillouin spectroscopy were used to investigate the polycrystalline NBT-7BT. The results revealed stress-dependent changes in elastic properties and the appearance of a transversal acoustic wave mode, which were similar to the changes in crystallographic structure and ferroelectric order.