“Frozen” phonon lmto-calculations for ferroelectric perovskites

Publisher Website
Google Scholar
Abstract
“Frozen” phonon calculations based on Density-Functional-Theory were performed for BaTiO3 and SrTiO3 with a full potential version of the linear-muffin-tin-orbital method. It was demonstrated that the ferroelectric instability in perovskites is the result of a delicate balance between forces produced by bonding and nonbonding states. Calculations of the electric field gradient at finite temperatures and its comparison to recent NMR-measurements in the tetragonal phase of BaTiO3 allow conclusions about the displacement-displacement correlation function.