Realization of face-shear piezoelectric coefficient d36 in PZT ceramics via ferroelastic domain engineering

The piezoelectric face-shear (d(36)) mode may be the most useful shear mode in piezoelectrics, while currently this mode can only exist in single crystals of specific point groups and cut directions. Theoretically, the d(36) coefficient vanishes in piezoelectric ceramics because of its transversally isotropic symmetry. In this work, we modified the symmetry of poled PZT ceramics from transversally isotropic to orthogonal through ferroelastic domain switching by applying a high lateral stress along the 2 direction and holding the stress for several hours. After removing the compression, the piezoelectric coefficient d(31) is found much larger than d(32). Then, by cutting the compressed sample along the Zxt +/- 45 degrees direction, we realized d(36) coefficients up to 206pC/N, which is measured by using a modified d(33) meter. The obtained large d(36) coefficients in PZT ceramics could be very promising for face-shear mode resonators and shear horizontal wave generation in nondestructive testing. (C) 2015 AIP Publishing LLC.