Propagation of Coupled Acoustic, Electromagnetic and Spin Waves in Saturated Ferromagnetoelastic Solids

We study the propagation of plane waves in an unbounded body of a saturated ferromagnetoelastic solid. Tiersten's equations form small fields superposed on finite initial fields in a saturated ferromagnetoelastic material are employed, with their quasi static magnetic field extended to dynamic electric and magnetic fields governed by Maxwell's equations for electromagnetic waves. Dispersion relations of the plane waves are obtained. The cutoff frequencies and long-wave approximation of the dispersion curves are determined. Results show that acoustic, electromagnetic and magnetic spin waves are coupled in such a material. For YIG which is a cubic crystal without piezoelectric coupling, the acoustic and electromagnetic waves are not directly coupled but they can still interact indirectly through spin waves.