External electric field effect on the properties of Bleustein-Gulyaev surface acoustic waves in lithium niobate and strontium titanate

The paper presents theoretical results for the effects of differently oriented external electric field on the velocity of Bleustein-Gulyaev surface acoustic waves (BG SAW) in lithium niobate and strontium titanate for different mechanical crystal states. It has been revealed that the BG SAW is unstable towards external effects, i.e. that the electric field not only alters its velocity, but it also yields the wave direction displacement. It is shown that, unlike the Rayleigh wave, the BG SAW exhibits a wave localization depth which substantially depends on the external effects.