Interfacial Effects On Magnetic Relaxation In Co/Pt Multilayers

Out-of-plane ferromagnetic resonance (FMR) spectra of sputtered Co/Pt multilayers with in-plane anisotropy were measured and analyzed by the Landau-Lifshitz-Gilbert equation. In order to explain the FMR linewidth, the extrinsic magnetic relaxation must be considered, in addition to the intrinsic Gilbert damping effect and the broadening induced by the magnetic inhomogeneity. The characteristic of the extrinsic magnetic relaxation is consistent with the two-magnon scattering model. The contributions of the intrinsic and the extrinsic magnetization relaxations decrease with increasing Co layer thickness, exhibiting an interfacial effect in the Co/Pt multilayers.