The piezoelectric shear strain coefficient of ⟨111⟩-oriented Pb (Zn1/3Nb2/3)O3-PbTiO3 piezocrystals

The piezoelectric d(15) coefficients of <111>-oriented (1-x)Pb(Zn1/3Nb2/3)O-3-xPbTiO(3) single crystals for x=0.045 and x=0.08 (PZN-4.5%PT and PZN-8%PT) have been measured as functions of dc bias field and frequency using a Zygo laser interferometer system. High d(15) values (similar to5500 pC/N for PZN-4.5%PT and similar to7500 pC/N for PZN-8%PT) were obtained in the absence of dc bias. d(15) decreased as the dc bias was increased. d(15) was also found to decrease with increasing frequency, and this frequency dependence decreased at sufficiently large bias fields. Our results suggest that these <111>-oriented crystals are promising materials for high performance shear transducers. (C) 2003 American Institute of Physics.