Effects of diffusion on magnetic excitations in films of yttrium iron garnet

Abstract

We have investigated the effects of a diffusion located at the yttrium iron garnet-gadolinium gallium garnet (YIG-GdGaG) interface on spin-wave excitations. We calculate at ambient temperatures that a localized or surface spin-wave mode can be excited in chemical vapor deposited but not in liquid phase epitaxy (LPE) films of YIG. This localized state can be excited for the magnetic field applied parallel but not perpendicular to the film plane, in agreement with experimental observations. The dependence of spin-wave intensities on the direction of the magnetic field, observed in LPE films, is explained in terms of a nonuniform distribution of the cubic magnetic anisotropy field at the interface.