Spin angular momentum absorption at the magnetic phase transition of Permalloy antiferromagnetic surface oxidized layers

We report an alternative mechanism for the physical origin of the temperature-dependent ferromagnetic relaxation of Permalloy (NiFe) thin films. By use of spin pumping experiments we demonstrate that the peak in the temperature-dependence of the NiFe damping can be understood in terms of enhanced spin angular momentum absorption at the magnetic phase transition of antiferromagnetic surface oxidized layers. These results suggest a new direction for the understanding of a least understood physical question, opening pathways for further investigations.