Frequency dependence of the parallel and perpendicular ferromagnetic resonance linewidth in Permalloy films, 2-36 GHz

Abstract
Ferromagnetic resonance linewidth data for 75% Ni‐25% Fe evaporated thin films at 2–36 GHz for both parallel and perpendicular orientations show that the two linewidths are the same and increase linearly with frequency above 10 GHz. At lower frequencies the parallel linewidth is in accord with the high‐frequency behavior, but the perpendicular linewidth levels off at 10–30 Oe. These data suggest that the high‐frequency relaxation is characteristic of a Landau‐Lifshitz λ‐type process but that the low‐frequency losses are characteristic of a process intermediate between λ‐type and 1/τ‐type relaxation.