Ferromagnetic resonance of amorphous Gd_1-xFe_x alloy thin films

Measurements of Ferromagnetic resonance are made on amorphous thin films of Gd_1-xFe_x alloy at room temperature. Their values of g-factor and magnetic anisotropy field are obtained as functions of composition. It is found that the compensation composition x_comp at room temperature decreases owing to a magnetic deactivation of Gd under the influence of residual gases during film deposition and furthermore decreases with the lapse of time owing to the same deactivation in air. In spite of the change in x_comp, their values of g-factor satisfy the Tsuya-Wangsness formula over a wide range of composition.