Monte Carlo simulation on the size effect in ferroelectric nanostructures

Abstract

The ferroelectric domain structures in a two-dimensional square lattice with different lattice sizes under a set of finite boundary conditions (zero dipole and clamped strain on lattice boundaries) are investigated using Monte Carlo simulation, based on the Landau phenomenological model. Given the finite boundary conditions, the ferroelectric domain structure evolves gradually from the 90°-striped pattern into the single-vortex pattern with reducing lattice size. When the finite boundary conditions apply only onto one-dimensional boundaries, as an approach to the case of thin films, the single-domain pattern is favored with reducing lattice size. The physics underlying the evolution of domain structures with varying lattice size is discussed.