Uniaxial-stress induced phase transitions in [001]C-poled 0.955Pb(Zn1∕3Nb2∕3)O3–0.045PbTiO3

First order rhombohedral to orthorhombic stress-induced phase transitions have been evidenced by bulk charge-stress measurements and x-ray diffraction derived lattice strain measurements in [001]C-poled 0.955Pb(Zn1∕3Nb2∕3)O3–0.045PbTiO3 (PZN-4.5PT). The transitions are induced by uniaxial compressive loads applied either along or perpendicular to the poling direction. In each case, they occur via rotation of the polar vector in the Cm monoclinic plane and the induced lattice strain is hysteretic yet reversible. Although no depoling is observed in the transverse mode net depolarization is observed under longitudinal stress which is important for the use of [001]C-poled PZN-PT and (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 single crystals in Tonpilz-type underwater projectors.