Magnetoelastic waves in ferromagnet plates and films

Abstract

The explosive development of investigations of magnetization waves in ferrite layers (plates and films) that occurred in recent years resulted in significant deepening and expansion of our conceptions of the effects of the interaction between such magnetization waves and elastic waves. The possibility of synchronization and hybridization of magnetization waves and elastic waves was shown in theory and experimentally for phase velocities of these waves in the direction of propagation along the ferrite layer exceeding the sound speed in the ferrite by one to two orders. At such phase velocities the inhomogeneous exchange energy often turns out to be insubstantial for magnetization wave propagation, and only the dipole energy is substantial. Therefore, we speak substantially about a new kind of magnetoelastic waves, the result of hybridization of pure magnetodipole and elastic waves. Such waves have been designated “fast magnetoelastic waves.” A brief survey of the theoretical, experimental, and applied investigations of fast magnetoelastic waves is contained in this paper. In the section “Theory” we present and discuss the fundamental equations, boundary conditions, and approximations necessary for the computation of fast magnetoelastic wave properties and the effects accompanying their propagation. The results of such computations currently known are presented. In the section “Experiments” we describe the fundamental requirements imposed on the specimens and the measurement methodology to detect and investigate the properties of fast magnetoelastic waves. Results of measurements executed at the present time as well as the prospects for further development in this direction are discussed.