Gilbert damping in single and multilayer ultrathin films: Role of interfaces in nonlocal spin dynamics - art. no. 217204

Unique features of the Gilbert damping in magnetic multilayers were investi gated by ferromagnetic resonance (FMR) using magnetic single and double lay er structures prepared by molecular beam epitaxy. The FMR linewidth for the Fe films in the double layer structures was larger than the FMR linewidth in the single Fe films having the same thickness. The additional FMR linewi dth scaled inversely with the film thickness, and increased linearly with i ncreasing microwave frequency. These results demonstrate that a transfer of electron angular momentum between the magnetic layers leads to additional relaxation torques.