Phase-field simulation of domain structure for PbTiO3/SrTiO3 superlattices

Phase-field modeling has been performed to study the domain morphologies of ferroelectric PbTiO3/SrTiO3 superlattice grown on SrTiO3 substrates. Taking into account contributions of the interfacial and depolarization field effects, the polarization, phase transition temperature and critical thickness are calculated as functions of sample dimensions and temperature. The results show that interfacial and depolarization field effects are the main reasons behind the dependence of the domain structures and critical properties (i.e., the phase transition temperature and critical thickness) on the thicknesses of the constituent layers of the PbTiO3/SrTiO3 superlattices.