Increased Gilbert damping in spin valves and magnetic tunnel junctions

We present a study on the Gilbert damping constant α in magnetic multilayers using the time-resolved MOKE technique. All observed α-values in Ni80Fe20 thin films with Cu/Ta seed and capping layers can be modeled using a spin pumping model. Investigation in device layers (spin-valves and magnetic tunnel junctions) is consistent with this model. An additional effect of the magnetization state of the pinned layer on free layer damping in spin valves is seen. These insights in the effect of interfaces on magnetic relaxation provide methods for optimization of magnetic devices for numerous high-speed applications.