Coupled magnetoelastic and electromagnetic waves in cubic ferromagnets in the region of reorientational phase transitions

Coupled magnetoelastic and electromagnetic waves in cubic ferromagnetic cry stals were studied theoretically in a magnetic field in the region of reori entational phase transitions (RPTs). It was shown that in ferrodielectrics, at certain values of the characteristics of a magnet, the dispersion relat ion of quasielectromagnetic waves at the RPT point has a quadratic dependen ce on the wave number, whereas the dispersion law of quasielastic waves is linear. In metals in weak magnetic fields, there are regions of wave number s in which the magnetoelastic waves become strongly damped. In strong magne tic fields in metals in the region of small wave numbers, the dispersion of propagating quasielectromagnetic waves (quasihelicons) is proportional to the fourth power of the wave number. Conditions were determined under which the magnetoelastic waves in ferromagnets can be considered independently f rom the electromagnetic waves. Conditions are also formulated under which v arious resonances are observed, in particular, a triple resonance.