We investigate the oxygen octahedral rotations that occur in two perovskites, SrTiO3 and PbTiO3, as a function of applied three-dimensional electric displacement field, allowing us to map out the phase diagram of rotations in both the paraelectric and ferroelectric regions of the polar response. First-principles calculations at fixed electric displacement field are used to extract parameters of a Landau-Devonshire model that is analyzed to identify the phase boundaries between different rotational states. The calculations reveal a rich phase diagram of rotations versus applied field in both SrTiO3 and PbTiO3, although the details are quite different in the two cases.
@article{arxiv.1212.0608,
title = {Electrically driven octahedral rotations in SrTiO3 and PbTiO3},
author = {Jiawang Hong and David Vanderbilt},
journal= {arXiv preprint arXiv:1212.0608},
year = {2013}
}