Dependence of interface motion on pressure in ferroelectrics

The motion of the paraelectric-ferroelectric interface in KNbO3 under hydrostatic pressure is studied in the framework of the mean-field theory. The kink solution is applied to the calculations of the width and velocity of the interface at different pressures. The calculations are based on the experimental data for the Curie-Weiss constant and the parameter of the Ginzburg-Landau expression for the free energy. The response to hydrostatic pressure and tricritical point is investigated nonempirically.