An investigation of large fatigue rate in <111>cub-oriented Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal

Domain structures in <111>cub-oriented 0.70Pb(Mg1/3Nb2/3)O3–0.30PbTiO3 (PMN–PT) single crystal have been investigated by both optical microscopy and transmission electron microscopy (all of the orientations below will be given in terms of the prototype cubic axes, denoted by the subscript cub). Microcracking in the fatigued PMN–PT crystal samples has been observed and its forming mechanism have been analyzed in terms of domain configurations. The contribution of microcracking to the large fatigue rate in <111>cub-oriented PMN–PT single crystal has been identified. A new approach that is based on observed domain configuration and microcracking has been proposed to explain the large fatigue rate in the <111>cub-oriented PMN–PT single crystal.