Phase-field simulations of thickness-dependent domain stability in PbTiO3 thin films

The phase-field approach is used to predict the effect of thickness on domain stability in ferroelectric thin films. The mechanism of strain relaxation and the critical thickness for dislocation formation from both the Matthews–Blakeslee and People–Bean models are employed. Thickness–strain domain stability diagrams are obtained for PbTiO3 thin films for different strain relaxation models. The relative domain fractions as a function of film thickness are also calculated and compared with experimental measurements in PbTiO3 thin films grown on SrTiO3 and KTaO3 substrates.