Angular Dependence of the Ferromagnetic-Resonance Field and Linewidth in Metal Plates

Abstract

We have calculated the 25 GHz ferromagnetic-resonance field and linewidth for a metal plate, whose properties correspond to those of Ni, with its static magnetization at an arbitrary direction with respect to the plane of the plate, and with an rf field applied at normal incidence. We assume an isotropic Landau-Lifshitz damping parameter, metallic conductivity, and either full pinning or no pinning of the magnetization at the surface. We find that the resonance linewidth varies strongly with angle, and that the value of linewidth and its angular dependence are strong functions both of plate thickness and of pinning condition. The shift in resonant field from its value for an insulator also depends strongly upon these parameters, but the angular dependence of the field is relatively small. The results, based on the isotropic Landau-Lifshitz relaxation model, do not account for the linewidth anisotropy observed in single-crystal nickel platelets.