Static shell model calculation of electrostriction and third order elastic coefficients of perovskite oxides

Abstract

Lattice dynamical calculations of electrostriction and third order elastic coefficients have been performed on the basis of a shell model for BaTiO₃, SrTiO₃ (both in the cubic phase) and for KTaO₃. Harmonic and anharmonic interactions arising from the Coulomb forces and from n.n. short-range central forces are included. The calculations refer to a static crystal and are based on empirical model parameters determined by fitting to experimental input data obtained by linear extrapolation to absolute zero.