Effects of viscous liquid on SH-SAW in layered magnetoelectric structures

We investigate analytically shear horizontal surface acoustic wave (SH-SAW) propagation in layered magnetoelectric structures loaded with viscous liquid, which involves a thin piezomagnetic layer bonded perfectly to an unbounded piezoelectric substrate. The dispersive relations are obtained and the effects of liquid viscosity on the phase velocity and attenuation of the waves are analyzed and discussed. From the results we can find that the effects of the liquid viscosity on the properties of SH-SAW are remarkable. The phase velocity decreases with increase of the viscous coefficient, or with increase of the frequency, and the attenuation increases with the frequency of the waves and the liquid viscosity, respectively. The relationship between attenuation and frequency or viscosity is nonlinear, but the former is a concave curve, whereas the latter is a convex curve. The attenuation decreases with the piezomagnetic coefficient, and increases obviously with the thickness of the layer. The analytical method and the results are useful for the design of acoustic wave devices based on magnetoelectric materials for liquid phase application, which could be resonated by either magnetic or electric fields.