Lattice dynamics of pure barium titanate and barium strontium titanate solid solutions

Abstract

The lattice dynamics of cubic BaTiO3 and Ba0.8Sr0.2TiO3 has been extensively investigated by inelastic neutron scattering using various triple-axis spectrometers. Measurements were carried out to obtain dispersion curves in the Gamma M, Gamma R and Gamma X directions of the Brillouin zone. A rigid-shell model has been developed for the pure BaTiO3, and for the mixed compound within the scope of a pseudo-unit-cell model. The branches measured are in good agreement with the theoretical calculations.