Raman spectrum in PbTiO₃re-examined: dynamics of the soft phonon and the central peak

Abstract

Light scattering measurements are investigated as a function of temperature from 10 to 900 K in the tetragonal and cubic phases of a PbTiO3 crystal. Phonon frequencies, ionic effective charges, spontaneous polarization and contribution to the dielectric permittivity are deduced from these data. The results show that the soft phonon and relaxation mode are both needed to describe the dynamics of this material.