Ferromagnetic resonance in iron at high temperatures

Abstract

We report FMR measurements on single-crystal whiskers of iron at 9 GHz for 300 ⩽ T ⩽ 1090 K. For 300 $ ̌ T $ ̌ 950 K the data are adequately explained by the Gilbert equation using a temperature independent relaxation parameter λ = 1.3 × 10 8sec -1 and g = 2.09. At higher temperatures, as reported earlier in the case of pure nickel, none of the existing phenomenological equations will give a reasonable description of the data unless both λ (or the equivalent relaxation time) and g are made functions of temperature.