Piezoelectric Shear Coefficients of Pb(Zn1/3Nb2/3)O3-PbTiO3 Single Crystals

Abstract
The piezoelectric and electromechanical properties of rhombohedral Pb(Zn1/3Nb2/3)O3–PbTiO3 (PZNT, PT<9%) single crystals in the shear mode are reported. PZNT8 single crystals poled along the direction with electrodes on the (110) faces (X cut) were found to have the electromechanical coupling factor reaching 97% and piezoelectric coefficients around 9200 pC/N. The high level of piezoelectricity of the single crystals is related to the high dielectric permittivity, with values of 17000. The pure shear mode can be obtained by using a Y cut (electrodes on (112) faces) PZNT single crystal with suitable size ratio. The electrical properties were limited to about 60°C for PZNT8 single crystal, the breakdown of the single domain state to multi-domain state temperature, being expanded to ~ 110°C for the PZNT4.5 composition.