Microstructure evolution and size effect of a two-dimensional barium titanate lattice sqaure have been studied using phase-field simulation. Based on the Landau phenomenological model, we calculated the microstructure evolution of the tetragonal and orthorhombic ferroelectric BaTiO3 started from a single domain with various lattice sizes. A direction-dependent hysteresis loop can be quantitatively described. The results show that both the phase transition with temperature and polarization switching under an external electric field are accompanied by multidomain and multiphase production in a l...
