Central peak inSrTiO3studied by dielectric spectroscopy

Abstract

Dielectric relaxation phenomena are studied in detail at the 107 K structural phase transition in ${\mathrm{SrTiO}}_3.$ These loss phenomena are explained in terms of the dynamics of domain walls that occur at the cubic-to-tetragonal phase transition and exist as precursor phenomena (locally ordered regions) in the high-temperature phase. We speculate that the same dynamics is responsible for the occurrence of a central peak in neutron-scattering experiments and we predict a relaxation rate of $1\times {10}^6{\sec }^{\mathrm{-}1}$ at the structural phase transition. Finally we compare our results with predictions of ${\Phi }^4$ lattice models.