Local residual stresses in pressure-treated barium titanate powders probed by inelastic light scattering

ABSTRACTProperties of the barium titanate submicron powder treated by high pressure were studied by Raman scattering. Residual mechanical stresses were estimated to be about 2 GPa in barium titanate powder treated under uniaxial pressure of 4 GPa. It is supposed that these mechanical fields change the characteristics of the central peak of the Raman spectra in the low frequency part. It is shown that central peak in pressure-treated powder corresponds to a broad distribution of relaxation times. Such behavior is typical for relaxors known as materials with the compositional disorder. Annealing decreases the residual mechanical stresses.