Ferroelectric system dynamics simulated by a second-order Landau model

By using a second-order time-dependent Ginzburg–Landau model, we simulate the dynamic polarization hysteresis behavior of a ferroelectric system subjected to a sinusoidal electric field. We examine polarization hysteresis loop structure as a function of both field amplitude and field frequency. The relationship between the latter and hysteresis loop area, i.e., hysteresis dispersion, is calculated. Departing from previous work that established that the considered model produces experimentally expected hysteresis dispersion in the low-frequency regime, we demonstrate that (i) this model also produces experimentally expected hysteresis dispersion in the high-frequency regime; (ii) this dispersion implies, in agreement with experimental observations, that system relaxation is characterized by an effective characteristic time which is inversely proportional to field amplitude when the latter is sufficiently high; and (iii) the considered model predicts a symmetry-breaking transition that depends on both field...