Anharmonic perturbation calculation of electrostriction for SrTiO₃

Abstract

The hydrostatic electrostriction coefficient of SrTiO₃ has been calculated as a function of temperature on the basis of anharmonic perturbation theory. The same anharmonic shell model as used before for the calculation of the electrostriction coefficients of the static crystal is employed. The anharmonic contributions from the Coulomb interactions are found to be comparable to those from the short-range interactions, and their inclusion leads to better agreement with experimental data than calculations based on the model of Bruce and Cowley.