We present the analytical study of stability loss and evolution of domain structure in inhomogeneous ferroelectric and ferroelastic samples for exactly solvable models. The model assumes a short-circuited ferroelectric capacitor (free ferroelastic) with two regions with slightly different critical temperatures Tc1 Tc2, where Tc1-Tc2 << Tc1, Tc2. We show that even a tiny inhomogeneity like 10-5 K results in splitting the system into domains below the phase transition temperature. At T < Tc2 the domain width a is proportional to (Tc1-T)/(Tc1-Tc2) and quickly increases with lowering temperature. The minute inhomogeneities in Tc may result from structural (growth) inhomogeneities, which are always present in real samples, and a similar role can be played by inevitable temperature gradients.
@article{arxiv.cond-mat/0207653,
title = {Formation and rapid evolution of domain structure at phase transitions in slightly inhomogeneous ferroelectrics and ferroelastics},
author = {A. M. Bratkovsky and A. P. Levanyuk},
journal= {arXiv preprint arXiv:cond-mat/0207653},
year = {2009}
}
Comments
9 pages, 3 figures. Much expanded in comparison with cond-mat/0112001 to include a model for inhomogeneous ferroelastics