STRUCTURE-ANALYSIS OF TB-FE AMORPHOUS FILMS USING EXTENDED X-RAY ABSORPTION FINE-STRUCTURE

Extended x-ray absorption fine structure analysis was employed to obtain insight into the influence of structural change on the magnetic and magneto-optical properties of Tb-Fe amorphous films. Films made by bias sputtering show a 20% lower density and a lower apparent coordination number of Fe atoms around an Fe atom than those made by nonbias sputtering. However, their interatomic distances are unaffected by the sputtering methods. After samples made by nonbias sputtering have been annealed, the atomic distances of Fe-Fe and Tb-Fe tend to increase and decrease, respectively, while the apparent coordination number, N*, and the structural disorder parameter, σ, increase and decrease, respectively, in association with a large deterioration in magnetic and magneto-optical properties. On the other hand, in the case of bias-sputtering films, samples annealed at 200 °C show a large decrease in magnetic anisotropy, Ku, but no significant change in individual atomic distances and apparent coordination number. However, the disorder parameter, σ, increases slightly on annealing at 200 °C.