LAUSR

AbstractPhase field simulations are conducted to investigate the frequency-dependent behavior of a ferroelectric single crystal with and without dislocation arrays. For the dislocation-free ferroelectric, both coercive field and remnant polarization increase with the increase in the applied electric field frequency. For the ferroelectric with dislocation arrays, however, the variation of remnant polarization with frequency depends on the amplitude of the applied alternating electric field. When the applied electric amplitude ranges from 0.3 to 0.7, called the low field, the remnant polarization increases first and then decreases. On the other hand, if the applied field amplitude is higher than 0.8, the remnant polarization does not change too much at low frequency (3.13 × 10−4–1.56 × 10−2), while it decreases sharply at high frequency (1.56 × 10−2–0.156). For various applied electric amplitudes ranging from 0.3 to 1.5, the overall trend of the coercive field is to increase in the low-frequency range, while it varies in the high-frequency range. The frequency-dependent properties are attributed to the generalized pinning and depinning of the dislocation arrays to polarizations, which is endorsed by the corresponding domain structures.