Evaluation of spin-orbit and dipole-dipole contributions to magnetic relaxation in iron near T c

The results for iron from measurements in the region near Tc of ferromagnetic resonance in high and low fields (GHz and 100 MHz) and of the lower-frequency ac susceptibility (kHz) are analyzed to extract the intrinsic damping parameters. The damping in excess of the contribution from spin-orbit coupling is attributed to dipole-dipole interactions. The theory of dipolar interactions developed by Raghavan and Huber for EuO is applied to iron.