Parametric spin-wave excitation in a ferrite single crystal with high anisotropy

A theoretical discussion is presented of the parametric excitation of spin waves in ferrite single crystals with high crystallographic anisotropy; it is shown that there are regions of sharp change in the spectrum and in the threshold fields that are related to the effects of the ellipticity and the overlap between the characteristic regions in the anisotropic spectrum for the thermal spin waves; the phenomena are analyzed for Ni -ferrite.