Anouar Njeh

Ordinary Differential Equation applied to ultrasonic wave Propagation in piezoelectric material

The propagation of ultrasonic waves is still a topic of interest due to its applications in surface acoustic wave devices (SAW). Research works related to propagation in various media as multilayer, thin film and semi infinite media can be found in the recent literature. Applications of these studies include technological areas as electronic systems and sensors. Acoustic wave propagation in piezoelectric media is basically achieved by the use of the ordinary differential equations method ODE. Our purpose is to elucidate how ODE is carried out leading to a best identification of the involved electromechanical partial waves. The eigenvector equation related to ODE method has been solved in three cases depending on the symmetry of the sagittal plane. Therefore the fundamental acoustic tensor is reformulated with respect to the existing coupling between the elastic partial waves and the electrical one. The new formulation of ODE is useful during propagation studies either in elastic materials or piezoelectric ones. The obtained results are illustrated on the well known piezoelectric material ZnO, which is assumed to be hexagonal.