Influence of thin conducting layer on leaky SH-SAW in piezoelectric crystal

The influence of a thin conducting layer on the characteristics of a leaky SAW propagating in a piezoelectric crystal (resisto-acoustic effect) was first theoretically and experimentally investigated. We studied the wave with shear-horizontal polarization (SH-SAW) in 36Y-X lithium niobate. As a result, the anomalous resisto-acoustic effect predicted previously for weakly inhomogeneous SAWs was revealed experimentally for the first time. The investigation showed that this effect is very sensitive to the real state of the crystal surface, which is defined by mechanical and chemical treatment of the sample. An assumption about the existence of a thin nonpiezoelectric layer with a disturbed structure on the crystal surface allowed good agreement to be reached between theoretical and experimental results.