Magnetoelastic waves in ferri- and antiferromagnetic crystals near spin reorientaional phase transission

Anomalous decrease of the sound velocity and the important role that nonlinear processes play near the spin-reorientational phase transitions (OPT) in the limited ferrimagnetic (FM) and antiferromagnetic (AF) crystals make such crystals promising materials for use in electronic devices [1]. The e5ciency of such devices can be raised considerably by using surface waves, since the energy of such waves is concentrated within a thin surface layer. The study of the spectra of magnetoelasic (ME) waves in limited specimens of FM and AF makes it possible to determine the type of soft mode involved in OPT.