Magnetic Properties and Magnetoresistance of Evaporated Fe-Si Films

抄録

Fe/Si films were prepared by evaporating Fe and Si alternately at various substrate temperatures T_s between 100 and 623K. The nominal thicknesses of Fe and Si were fixed at 3.4Å and 6Å, respectively. The films prepared at T_s higher than 200∼300K showed a superparamagnetic behavior, and also an isotropic magnetoresistance (MR) of 0.02%. On the other hand, the films at lower T_s showed an anisotropic MR similar to that observed in most ferromagnets. These results suggest that the film structure is changed from a granular like one at low T_s to a partially a continuous one at high T_s. These structure changes may come from an interdiffusion and/or a reaction between Fe and Si in the films.