PIEZOELECTRIC SURFACE WAVES IN CUBIC AND ORTHORHOMBIC CRYSTALS

Abstract

The existence of a piezoelectric surface wave, which does not arise in nonpiezoelectric materials has been reported in hexagonal crystals by Bleustein and Gulyaev. In this letter, similar waves are reported to exist in cubic crystals of 23 and 4̄3m classes and orthorhombic crystals of mm2 class. Velocity equations for the piezoelectric surface waves in these symmetry classes are presented. It has been demonstrated that the velocities are always smaller than the piezoelectrically stiffened but always larger than the unstiffened bulk shear waves in the corresponding direction of propagation. Numerical results for the particular examples of Bi₁₂GeO₂₀(23) and Ba₂NaNb₅O₁₅(mm2) are also presented.