Geometrical-Optics Approximation for Bulk Spin Waves in Spatially Nonuniform Ferromagnetics with a Biaxial Magnetic Anisotropy

摘要

Refraction index of spin waves, which propagate in a ferromagnetic medium with inhomogeneous distribution of the parameters of exchange interaction, uniaxial and rhombic anisotropy, is calculated within the formalism of spin density. The coefficients of spin-wave reflection and transmission are computed on a boundary of two homogeneous magnetic media with different constants of exchange interaction, uniaxial and rhombic anisotropy, and saturation magnetization. The dependences of both intensity of a reflected wave and refractive index on a wave frequency and value of external permanent homogeneous magnetic field are obtained.