Temperature stability of the piezoelectric and elastic response of dc biased 001 and 110 oriented Pb(Zn1/3Nb2/3)O-3-PbTiO3 single crystals
Temperature and field dependent investigations of the longitudinal electromechanical properties of - and -oriented 0.955Pb(Zn1/3Nb2/3)O-3-0.045PbTiO(3) single crystals have been performed. Electromechanical equivalence was found between  and  orientations in the ferroelectric rhombohedral FEr phase region, but not in the ferroelectric tetragonal FEt one. A dc bias of 0.4 MV/m did not affect this equivalence. Softening of the dielectric constant (K), piezoelectric coefficient (d(33)), and Young's modulus (Y) were observed along both the  and  orientations in the FEr phase region on heating towards the FEt one. Above the FEr-FEt phase transition, a significant anisotropy was observed in the electromechanical and elastic coefficients. These results demonstrate that the enhanced length extensional (33-mode) electromechanical coupling k(33) of rhombohedral crystals far from the morphotropic phase boundary is not constrained to the <001> orientation, but rather to the (110) plane. (C) 2004 American Institute of Physics.