SCANNING ELECTRON-MICROSCOPY OBSERVATION OF SURFACE-ACOUSTIC-WAVE PROPAGATION IN THE LINBO3 CRYSTALS WITH REGULAR DOMAIN-STRUCTURES

This paper reports a scanning electron microscopy investigation of surface acoustic wave propagation in the LiNbO3 crystals with regular domain structures. The regular domain structures in the LiNbO3 crystals were formed by the method of the thermo-electric treatment after growth. We investigated two modes of the interaction between the surface acoustic waves and regular domain structures in the LiNbO3 crystals: excitation of the surface acoustic waves by the curved regular domain structure, and propagation of the surface acoustic waves along and across the regular domain structures. It is shown that the regular domain structure in the first case can be used as an interdigital transducer for excitation of the surface acoustic waves through the longitudinal piezoelectric effect. In the second mode of the interaction we observed that the regular domain structure can be used as an acoustic wave-guide in the process of the propagation of the traveling surface acoustic waves along the regular domain structure. Also, we demonstrate the reflection of the surface acoustic waves from the domain walls in the process of surface acoustic wave propagation across the regular domain structure.