Kinetically stabilized metastable polarization states in ferroelectrics

By directly using experimental hysteresis loop data, a Landau theory-based model has been developed to investigate the effects of externally applied stimuli (electric field, stress, and temperature) on the average, time-dependent response in ferroelectric ceramics. For both PLZT and BNT-BT-KNN systems, experimentally observed (macroscopic) metastable states are a result of a free energy minimum that develops at a zero polarization state when the sample is subject to an externally applied field. Additionally, the frequency dependent hysteresis response demonstrates that a transition between relaxor ferroelectric and antiferroelectric develops at a critical cycling frequency, in agreement with the literature. The appearance of frequency-induced and electric field amplitude-induced kinetically stabilized phases is proposed and summarized in terms of frequency-stress and frequency-temperature response maps.