Measurements of face shear properties in relaxor-PbTiO3 single crystals

The face (contour) shear piezoelectric properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) single crystals were experimentally determined by the impedance method. Zt ± 45° cut samples with various aspect ratios were investigated based on Bechmann’s zero-order approximate solution. Square plates were found to exhibit a clean face shear vibration mode and the experimental data were in good agreement with the rotated matrix calculations and finite element method simulations. The piezoelectric coefficients d36 were determined to be in the range of 1600-2800 pC/N, depending on the compositional variations, with an ultralow frequency constant N36, in the range of 490–630 Hz.m. In contrast to conventional thickness shear modes, the mechanical quality factors of face shear vibrations are relatively high, with Q values being on the order of ∼100-450, demonstrate promising for low frequency transducer applications.