Electroacoustic surface waves on moving boundaries

Electroacoustic surface waves that propagate along the 180 degrees domain w all of tetragonal ferroelectric and along the surface where the polarizing field in the electrostrictive material has a discontinuity are considered. These boundary surfaces shift transversely (with respect to the wave propag ation) at a constant velocity. It is found that, due to the boundary shift, the electroacoustic wave vector acquires a transverse component aligned wi th the boundary motion. The changes of the wave parameters affected by the transverse boundary motion are relative and depend on the observer's positi on: in the boundary rest system, the electroacoustic wave becomes slower an d is localized, while, in the laboratory system, its phase velocity increas es and oscillations are delocalized with respect to the boundary. It is sho wn that, in ferroelectrics with high electromechanical coupling and electro strictive dielectrics polarized by high-intensity fields, the electroacoust ic-wave localization region on the moving boundary does not exceed several wavelengths; therefore, a moving boundary can provide the electroacoustic w ave translation.