Relaxation mechanism driven by spin angular momentum absorption   throughout antiferromagnetic phase transition in NiFe surface oxides
  We report an alternative mechanism for the physical origin of the temperature-dependent ferromagnetic relaxation of Permalloy (NiFe) thin films. Through spin-pumping experiments, we demonstrate that the peak in the temperature-dependence of NiFe damping can be understood in terms of enhanced spin angular momentum absorption at the magnetic phase transition in antiferromagnetic surface-oxidized layers. These results suggest new avenues for the investigation of an incompletely-understood phenomenon in physics. 
L. Frangou, G. Forestier, S. Auffret, S. Gambarelli, and V. Baltz
cond-mat.mtrl-sci