Spin-Wave Instabilities in Magnetic Thin Films

Abstract

High-power resonance effects have been observed in thin films of Permalloy. These effects are characterized by a saturation of the main resonance and in some cases the growth of a subsidiary absorption peak at magnetic fields below resonance. The hcrit associated with the saturation of the main resonance is found to be sensitive to the film thickness. The size dependence of nonlinear effects in films seems to be associated with a distortion in the spin-mode dispersion relation at low k numbers.