Damping of ferromagnetic resonance in NiFe alloys

Abstract

From linewidth data of bulk (110) NiFe alloy single crystals (100 to 45 wt% Ni) at 19.5 and 26 GHz Landau-Lifshits damping parameters were derived, which, except for 100% Ni, increase with temperature between — 196 °C and the Curie point. The λ values of the alloys are found to be considerably lower than for pure Ni. For 75% Ni, λ shows a very pronounced decrease with increasing degree of order. The λ dependence on frequency, temperature, alloy composition, and state of order is in qualitative agreement with a relaxation model on the basis of spin—orbit effects within a band picture proposed by Kamberský.