Piezoelectric 36-shear mode for [011] poled 24%Pb(In1/2Nb1/2) O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ferroelectric crystal

Superior piezoelectric 36-shear mode of [011] poled Pb(Mg1/3N1/3)O-3-PbTiO3 (PMN-PT) in zxt+/-45 degrees cut direction is the first practical piezoelectric 36-shear mode reported [P. Han, "Piezoelectric crystal elements of shear mode and process for preparation," U.S. patent 7,908,722 B2 (2004)]. The investigation on the piezoelectric 36-shear mode of PIN-PMN-PT crystal was carried out and summarized in this paper. The [011] poled 24%Pb(In1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PIN-PMN-PT) crystal was chosen for the study owing to its large coercive electrical field and high de-poling temperature. Following an introduction to the concept of the piezoelectric 36-shear mode and targeting to explore the maximum d(36), we have performed the theoretical calculation on d(36) by coordinate transformation of a third rank tensor. To verify the results of the calculation, the d(36) was measured by two ways: strain measurements (piezoelectric converse effect) and charge measurements (piezoelectric direct effect) on the same composition crystal. It has been distinguished and determined that the maximum d(36) piezoelectric coefficients occurred in the zxt + 45 degrees cut direction for negative and in the zxt-45 degrees cut direction for positive, respectively. The electromechanical coupling factor k(36) was also studied. The occurrence of the maximum d(36) up to 2400 pC/N and the large electromechanical coupling factor k36 as high as 87.8% were theoretically and experimentally confirmed on zxt +/- 45 degrees cut, [011] poled 24%PIN-PMN-PT piezoelectric crystals. The 36-shear mode PIN-PMN-PT crystal enables the piezoelectric performance under high electrical field driving. (C) 2012 American Institute of Physics. [doi:10.1063/1.3682478]