Ultrahigh transverse strain and piezoelectric behavior in (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 crystals

Electric-field-induced transverse strain behavior of (1−x)Pb(Mg1∕3Nb2∕3)O3-xPbTiO3 (PMNT∕x) crystals with different cuts and compositions was investigated for using as electromechanical actuators. High transverse strain with low hysteresis was achieved for rhombohedral crystals near morphotropic phase boundary (28⩽x⩽30). Optimum crystallographic cut was found to be pseudocubic [001]L×[1¯10]W×[110]T for rhombohedral crystals, exhibiting high transverse strain S1∼−0.33% with hysteresis ∼8% and ultrahigh piezoelectric coefficient (d31)∼−3100pC∕N. When E field <6kV∕cm, the strain versus E-field curve is approximately linear, without obvious hysteresis. negative E field of −1.5kV∕cm can be applied to PMNT∕x crystals with minimal hysteresis. However, strain behavior of PMNT∕x crystals cut into [01¯1]L×[2¯11]W×[111]T or [100]L×[010]W×[001]T did not exhibit excellent properties as we expected. High transverse strain with low hysteresis makes PMNT∕x crystals promising candidates for high-performance strain actuators.