Phase-field simulations on the electrocaloric properties of ferroelectric nanocylinders with the consideration of surface polarization effect

Abstract

Due to the symmetry breaking on surfaces of a ferroelectric crystal, the polarizations on surfaces are different from those inside the crystal. To describe this surface polarization effect which depends on the surface atomic termination, the extrapolation length is incorporated in the phase-field method based on the time-dependent Ginzburg-Landau equation to investigate different surface polarizations and their influence on the electrocaloric properties in PbTiO3 nanocylinders. The simulation results show that the extrapolation length can alter the maximum value of the adiabatic temperature change and shift its temperature location.