Harmonic analysis of ferroelectric polarization dynamics simulated by a second-order Landau model

By using a second-order time-dependent Ginzburg-Landau model, we simulate the 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. Departing from previous work, the relationship between these field parameters and loop structure is quantified by considering the Fourier transform spectra of the time series of polarization. These spectra are used to determine deforming factors that measure the amplitude- and frequency-dependent distortions of hysteresis loop structures from ellipticity. Our results agree with experimental observations, thus validating the model.