Electromechanical and elastic isotropy in the (011) plane of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 crystals:: Inhomogeneous shearing of polarization

Temperature dependent electromechanical investigations of <110>, <001>, and <111> oriented morphotropic phase boundary compositions of Pb(Mg1/3Nb2/3)O-3-PbTi0(3) crystals have been performed. Softening of the dielectric constant, piezoelectric constant, and Young's modulus was found for all three orientations, near a ferroelectric rhombohedral to ferroelectric tetragonal transformation. However, the value of Young's modulus was an order of magnitude higher along <111>, than either <001> or <110>. An unusual electromechanical and elastic equivalence was found between the <110> and <001> directions. This result demonstrates that the enhanced electromechanical performance of oriented piezocrystals is not constrained to the <001> orientation, but rather to the (011) plane. (C) 2002 American Institute of Physics.