Love waves in layered piezoelectric/piezomagnetic structures

The propagation of Love waves in layered structures is investigated for two cases: a piezomagnetic (PM) layer on a piezoelectric (PE) half-space and the reverse configuration. The dispersion relations are obtained in explicit form. The numerical examples are provided to illustrate the variations of the phase and group velocities versus the wavenumber for the combinations of different materials. The results show that: (1) the phase and group velocities initiate at the bulk shear wave velocity of the half-space medium and approach the bulk shear wave velocity of the layer with increasing wavenumber; (2) the influence of the magnetic permeabilities of PE materials on the phase velocity can be neglected; (3) for the layered medium consisting of a PM layer and a PE half-space, the properties of PE materials have a great influence on the phase and group velocities at lower wavenumber for the lowest mode. These findings are useful for PE/PM composite media or structures in the microwave technology. (C) 2008 Elsevier Ltd. All rights reserved.