Effect of stress on phase transition of ferroelectric films

The effect of stress on the ferroelectric-paraelectric phase transition temperature of ferroelectric thin films has been evaluated using a modified planar-type four-state Potts model. In this model, it is assumed that the electromechanical effect is induced by the association between the dipole orientation and the strain state in individual perovskite cells. The mechanical energy density, which is equal to the product of stress and strain, gives rise to the additional contribution to the system Hamiltonian. The rotation of dipoles, governed by the change in Hamiltonian as in the usual Metropolis algorithm, gives rise to various ferroelectric properties. The shift in phase transition in the presence of transverse stress is demonstrated and compared with experimental results based on the position of the susceptibility peak