清浄雰囲気で作製したα"-Fe_<16>N_2スパッタ薄膜の構造と飽和磁化  [in Japanese] Structure and Saturation Magnetization of α''-Fe_<16>N_2 Thin Films Fabricated by Means of an Ultra-Clean Sputtering Process  [in Japanese]

α"-Fe_<16>N_2 films were fabricated by means of an ultra-clean sputtering process (UC process). The impurity oxygen content of iron films fabricated by this process was 0.2at%, one-fifth of that of films fabricated by the normal process. Dry etching of the substrate surface with rf plasma before film deposition increased the crystallinity of the films. The mean diameter of the grain size of UC processed α'-Fe-N martensite was 1.5-2.0 times larger than that of films fabricated by the normal process. The degree of the preferred grain orientation of UC-processed α"-Fe_<16>N_2 films was superior to that of films fabricated by the normal process. The saturation magnetization of α"-Fe_<16>N_2 films fabricated by the UC process was at most 240emu/g, the same as that of films fabricated by the normal process.