Macroscopic elastic and electric fields in ferroelectrics: Phenomenology and simulations

A 3D solution for electrostriction govemed elastic field is obtained in terms of integral transformations. In particular, the nonlocal elastic interaction term in the free energy functional is derived for any point symmetry. Applicability of the free energy functional to phenomena specific to ferroelectric relaxors is discussed and the role of multiplicative noise emphasised. A simplified model potential is used to demonstrate the contribution of fluctuations to external field controlled domain reorientation.