Extrinsic contributions to spin-wave damping and renormalization in thin Ni50Fe50 films

Ferromagnetic resonance has been used to study the room-temperature linewidth and frequency shift of the q=0 spin-wave mode in thin films of NiFe sputtered on Si(100) substrates. The data on the variation of the linewidth and resonance field with film thickness are completely consistent with the extrinsic mechanism recently proposed by Arias and Mills based on momentum nonconserving two-magnon scattering off defects on the film surfaces.