Transverse-Mode Properties of [011]-Poled Pb(Zn1/3Nb2/3)O3–PbTiO3 Single Crystals: Effects of Composition, Length Orientation, and Poling Conditions

Abstract

The poling responses of [011]-poled Pb(Zn1/3Nb2/3)O3–PbTiO3 [PZN–PT] single crystals of a range of compositions and two length orientations have been investigated. The results show that [011]-poled PZN–PT single crystals of [100]-length-cut exhibit much superior transverse properties than [011]-length-cut crystals. Extremely high d31 values of -(3000–4000) pC/N and k31∼0.90–0.96 were obtained for PZN–7%PT optimally [011]-poled crystals. This composition, however, shows degraded dielectric and piezoelectric properties when poled at ≥0.6 kV/mm. In contrast, PZN–4.5%PT and PZN–6%PT single crystals show no signs of overpoling even when poled up to 2.0 kV/mm, exhibiting d31≈-(2700–3200) pC/N and k31∼0.90–0.92 (for PZN–6%PT) and d31≈-1500 pC/N and k31∼0.86–0.90 (for PZN–4.5%PT), respectively. The presence of certain amounts (i.e., 10–15%) of orthorhombic phase in a rhombohedral matrix has been found to be responsible for the superior transverse piezoelectric properties of optimally [011]-poled PZN–(6–7)%PT.