Simulation of metal layers thickness influence on phase velocities of acoustic waves in the piezoelectric plates

The research work presents the results of computer simulation of mass loading influence represented by two metal layers on variations in the dispersion modes of the Lamb and SH elastic waves phase velocity in the piezoelectric lay- ered structures Me/ZnO/Me and Me/AlN/Me depending on the elastic wave frequency and the ratio of the metal layer thickness to the piezoelectric layer thickness. The studied materials of the piezoelectric layers have a set of such sig- nificant properties as large values of the electromechanical coupling coefficient for piezoelectrics and significant val- ues of phase velocities for bulk waves and surface acoustic waves. Aluminum (Al) and molybdenum (Mo) are consid- ered as metal layer materials, which are most often used in the manufacturing of acoustic electronic devices. For both types of structures it was revealed that only the Lamb elastic wave modes have localized maxima of S sensitivity. It was found that the value of changing in the elastic wave phase velocity depends on the ratio of the metal layer acoustic im- pedance and the piezoelectric plate material. The maximum sensitivity values of elastic wave modes are achieved with Al/AlN/Al configuration, i.e., in a system with low acoustic impedance values of the bulk longitudinal wave for the layer and piezoelectric plate materials. The results of the simulation can be used in the development of various acousto- electronic devices, including some components of the rocket and space technology electronic base.