ターゲット : 基板間距離を変えて作製したFe_xCo_<1-x>-Al_2O_3グラニュラー薄膜のGMRと微細構造  [in Japanese] Target-Substrate Distance Dependences of GMR and Microstructure in Fe_xCo_<1-x>-Al_2O_3 Granular Thin Films  [in Japanese]

The magnetic properties and magnetoresistance of Fe_xCo_<1-x>-Al_2O_3 thin films were studied by changing the target-substrate distance (D_<T-S>) from 65 to 12 0mm. The films were prepared by rf magnetron sputtering. The MR ratio of Fe_<0.2>Co_<0.8>-Al_2O_3 thin films increased with increasing D_<T-S>. An MR ratio of 7.3% was obtained in a film with D_<T-S> of 120mm at room temperature. The MR ratio and the MR sensitivity of Fe_xCo_<1-x>-Al_20_3 thin films exhibited a maximum at about x=0.2. From an analysis of the structure, it is considered that the enhancement of the MR ratio is related to enlargement and small distriburion of the macroscopic grain size in the films.