Magnetoelastic Rayleigh waves propagating along a tangential bias field on a YIG substrate

The propagation characteristics of magnetoelastic (ME) Rayleigh waves on a YIG substrate are treated for the parallel bias configuration, wherein the bias field is tangential to the substrate and parallel to the direction of propagation. The YIG surface is considered to be mechanically free and either adjoined to vacuum (unmetallized configuration) or electrically shorted by a thin perfectly conducting metallic film (metallized configuration). The ME Rayleigh waves are found to be bound surface waves outside of a spectrum of frequencies given approximately by the magnetostatic bulk-wave spectrum, and of the leaky type within it. By varying the frequency (or equivalently the bias field) over the leaky-wave spectrum, the direction of energy leakage into the substrate may be controlled over an angle of 180°from the direction of surface-wave propagation.