Finite-temperature atomic structure of 180° ferroelectric domain walls in PbTiO₃

School of Civil and Environmental Engineering, Georgia Institute of Technology - Atlanta, GA 30332, USA

Corresponding author: arash.yavari@ce.gatech.edu

Received: 24 December 2009
Accepted: 15 April 2010

Abstract

In this letter we obtain the finite-temperature structure of 180° domain walls in PbTiO₃ using a quasi-harmonic–lattice dynamics approach. We obtain the temperature dependence of the atomic structure of domain walls from 0 K up to room temperature. We also show that both Pb-centered and Ti-centered 180° domain walls are thicker at room temperature; domain wall thickness at T = 300 K is about three times larger than that of T = 0 K. Our calculations show that Ti-centered domain walls have a lower free energy than Pb-centered domain walls and hence are more likely to be seen at finite temperatures.