Influence of a thin layer with arbitrary conductivity on the characteristics of acoustic waves in potassium niobate

The influence of a thin layer of arbitrary conductivity on the characteristics of acoustic waves in potassium niobate is investigated theoretically. The conductivity of a thin layer on the surface of a potassium niobate crystal or plate is shown to have a significant influence on the damping and velocity not only of symmetric Lamb waves and quasi-shear-horizontal waves but also of Gulyaev-Bleustein waves. It is found that a relative change in velocity as large as 50% can be achieved for quasi-shear-horizontal waves by altering the surface conductivity. The results obtained reveal great prospects of using potassium niobate to create acoustoelectronic devices with controllable characteristics.