Ferromagnetic resonance linewidth for NM/80NiFe/NM films (NM = Cu, Ta, Pd and Pt)

The out-of-plane angular dependence of ferromagnetic resonance linewidth of non-magnetic metal (NM)/ 80NiFe(Py)(20-100 A)/NM (NM = Cu, Ta, Pd and Pt) sputtered films were measured for the investigation of magnetic damping. The linewidth for NM = Pd and Pt were larger than that of NM = Cu and Ta. Analysis of the angular dependence of the linewidth using Landau-Lifshitz-Gilbert equation with magnetic inhomogeneities showed that the Gilbert damping parameter, G, for NM = Pt and Pd were larger than the bulk value of Py and were dependent on the thickness of Py. G, for NM = Cu and Ta were same as the bulk value. These results show that the magnetization precession of Py layers sandwiched by Pt or Pd layers damps more rapidly.