Orientation-tunable ferroelectric and energy storage properties in PMN-PT single crystals

The ferroelectric, dielectric and energy storage properties of (1 - x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) (PMN-PT) can be changed by altering the concentration of PbTiO3, but a wider scope for performance improvement can be opened by regulating the crystal orientation. Herein, we investigated the orientation dependence of the ferroelectric and energy storage performance of 0.7PMN-0.3PT single crystals with (001), (011), and (111) orientations. An excellent ferroelectric characteristic is obtained in the (111)-oriented PMN-PT single crystals owing to the spontaneous polarization lying along the (111) orientation in the rhombohedral phase. The (001)-oriented PMN-PT exhibits the greatest energy storage efficiency of 64.95% at E = 12 kV cm(-1) among the studied crystals, which is attributed to the smallest ratio of remnant polarization to saturation polarization for unipolar polarization-electric field loops. Particularly, a rhombohedral to orthorhombic phase transformation is observed with increasing temperature for the (001)-oriented PMN-PT, affording the largest polarization at high temperature. All the PMN-PT single crystals exhibit excellent antifatigue performance and temperature stability on energy storage.