Surface Acoustic Waves Propagating In Layered Magneto -electric Material Structures

Surface acoustic waves (SAWs) are widely used in the fields of communications, electromagnetic countermeasure (ECM), and such as sensors, resonators, etc. The propagating behaviors of SAW are affected by the material properties of layer and substrate. It has great significance to study the effects of the constants of materials, thickness of thin layer and boundary conditions. Based on the linear piezoelectric-piezomagnetic theory and elastic waves in solids, the following problems are investigated in this dissertation:(1) We investigate surface acoustic waves (Rayleigh waves) in a magneto-electro-elastic material structure of half-space. The magneto-electrically open and shorted conditions at the surface are taken to solve this problem. The phase velocity can be numerically calculated and figured for the magneto-electrically open and shorted cases, respectively, for different piezomagnetic coefficient.(2)We investigate surface acoustic waves in a layered piezomagnetic material structure. The magnetic open and shorted conditions at the surface are taken to solve this problem. The phase velocity can be numerically calculated and figured for the magnetic open and short cases , respectively, for different piezomagnetic coefficient. The results can be used to the piezomagnetic resonators and sensors.(3) We investigate surface acoustic waves in magneto-electro-elastic material layered structures where a thin magneto-electro-elastic layer bonded to a semi-infinite elastic substarte. The magneto-electrically open and shorted conditions at the surface are taken to solve this problem. The phase velocity can be numerically calculated and figured for the magneto-electrically open and shorted cases, respectively, for different piezomagnetic coefficient. The methods and procedures can be applied to surface acoustic wave analysis in the magneto-electro-elastic structures used in acoustic wave resonators and sensors.(4) Furthermore we investigate surface acoustic waves in layered magneto-electro-elastic structures where a thin piezomagnetic layer bonded to a semi-infinite piezoelectric substrate. The governing equations of the Rayleigh waves can be obtained on the basis of the linearly magneto-electro-elastic theory. The displacements, electric potential, magnetic potential, stresses, electric displacement, and magnetic induction are continuous across the interface of the thin layer and the substrate together with the traction free and the magneto-electrically open and shorted conditions on the surface of the structure. The methods and procedures can be applied to surface acoustic wave analysis in the magneto-electro-elastic structures used in acoustic wave resonators and sensors.(5) We investigate analytically Love waves in layered piezomagnetic/piezoelectric structures loaded with viscous liquid, which involves a thin piezomagnetic layer bonded perfectly to an unbounded piezoelectric substrate. The effects of viscosity of liquid on the phase velocity and attenuation of Love waves are analyzed. The numerical results are presented and discussed. The analytical method and the results can be useful for the design of the chemical and the biosensing liquid sensors of magnetoelectric materials.