Electrostrictive effect in Pb(Mg1/3Nb2/3)O3-xPbTiO3 crystals

The electrostrictive effect was investigated in Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) (PMN-xPT) relaxor ferroelectric crystal, a representative high performance piezoelectric material, with respect to orientation, temperature, and composition. The electrostrictive coefficients Q(11)(C), Q(12)(C), and Q(44)(C) of PMN-xPT (x = 0.25-0.37) crystals were found to be on the order of 0.055, -0.024, and 0.020 m(4)/C-2, respectively. The maximum and minimum Q(33)* were found to be along < 100 > and < 111 > directions, being about 0.055 and 0.014 m(4)/C-2, respectively, showing a strong anisotropic behavior, which is inherently associated with the oxygen-octahedra structure. In contrast to piezoelectric and dielectric responses, the electrostrictive coefficients Q are found to be insensitive to the ferroelectric phase transition, no matter it is induced by the temperature or composition. (C) 2013 AIP Publishing LLC [http://dx.doi.org/10.1063/1.4802792]