Magnetoelastic waves in thin films

Abstract: This paper discusses the physics of magnetoelasticity and magnetoelastic waves as well as their mathematical description. Magnetoelastic waves occur as a result of strong coupling between spin waves and elastic waves in magnetostrictive ferromagnetic media. In a first part, the basic behavior of spin waves is reviewed in both bulk ferromagnets as well as in thin films. Next, elastic waves are discussed with a focus on thin films. Finally, the interactions between the elastic and magnetic domains are described and it is shown how this results in the formation of magnetoelastic waves. Based on the description of bulk magnetoelastic waves, a theory for magnetoelastic waves in thin films is developed and their dispersion relations are derived. It is shown that the behavior strongly depends on the geometry of the system, especially on the polarization of spin and elastic waves and the direction of the magnetization of the magnetostrictive ferromagnet.