Polarization switching in PbTiO<sub>3</sub>: An ab initio finite element simulation
E. B. Tadmor, U. V. Waghmare, G. S. Smith and E. Kaxiras
Acta Materialia, 50, 2989-3002 (2002).

ABSTRACT
A continuum constitutive model for PbTiO<sub>3</sub> has been obtained from an
effective Hamiltonian which was constructed from ab initio calculations. This
model contains the nonlinearities necessary for switching from the ground-state
tetragonal phase to the metastable rhombohedral and orthorhombic phases. The
constitutive model was incorporated into a finite element formulation in order
to study the large length-scale electro-mechanical response of this
piezoelectric material. We use this approach to study the hysteresis of
single-crystal PbTiO<sub>3</sub> as a function of applied electric field and
temperature and we analyze the microscopic mechanisms responsible for
polarization switching. The model successfully reproduces the qualitative
features of a high-strain actuator recently proposed and tested experimentally.