Electric-field-induced polarization fatigue of [001]-oriented single crystals

Electric fatigue tests were carried out on [001]-oriented Pb ( Mg 1 / 3 Nb 2 / 3 ) O 3 – 0.32 PbTiO 3 (PMN–0.32PT) single crystals at different electric fields: lower and higher than the coercive field. For the crystals fatigued at low (1.5 kV/cm) electric field, the polarization fatigue and piezoelectric constant degradation are weak (<20%) and can be easily removed by thermal annealing, and it is found that the fatigue behavior is mainly due to the phase transition and the introduction of intermediate phase(s) during the fatigue process. For the crystals fatigued at high (7.5 kV/cm) electric field, a severe fatigue behavior (∼40%) is observed in the polarization, and the piezoelectric constant and the fatigue are difficult to eliminate by thermal annealing. It is believed that for the samples fatigued at high electric field, besides the contribution of the phase transition and the introduction of intermediate phase(s) during fatigue, domain wall pinning is the key contribution to the observed severe fatigue behavior. It is also found that the fatigue causes the crystal to have a different strain response: a more gradual response and with a smaller maximum strain response.