The effect of nonlinear stress and temperature on the ferroelectric properties of perovskites. Part 2: modeling results

Abstract

The results obtained from the model developed in Part I are discussed in this paper. In Part I, Landau free energy formulation is used to drive the coupled electric field – stress – polarization – temperature equations. Two new parameters, temperature at which dielectric stiffness appearing with second order polarization terms changes sign and the nonlinear elastic stiffness, are included in the free energy resulting in additional terms in the coupled field equations. Effect of temperature, electric field and various stress boundary conditions are simulated and compared with available experimental results. In particular, Barium Titanate and Lead Titanate ferroelectric behavior is simulated. The simulations reveal tricritical points, metastable equilibrium and stress induced property variations for both Barium Titanate and Lead Titanate. The simulations are compared to the experimental data.