基板加熱スパッタによるSmFe_<12>/α-Fe系ナノコンポジット薄膜の作製  [in Japanese] Fabrication of SmFe_<12>/αFe Nanocomposite Films by rf-Sputtering onto Heated Substrates  [in Japanese]

Highly aligned SmFe_<12>/α-Fe nanocomposite thin films were fabricated by rf magnetron sputtering onto heated glass substrates. The volume fraction of the α-Fe phase (V_<Fe>) was adjusted systematically by putting a different number of Smtips (5×5mm^2) on the Fe target. Nearly single-phase SmFe_<12> films of ThMn_<12>-type structure with the (001) plane aligned parallel to the film plane were synthesized at a substrate temperature T_s of 550℃ by using 28 sm tips. These films exhibited good squareness in the demagnetization curve. By redicing the number of Sm tips to 12 and keeping the substrate temperature Ts at 550℃, we fabricated nanocomposite films with different V_<Fe>'s. Two different series of film structures with and without Ti underlayers (50 nm) were fabricated, and Ti capping layers (50 nm) were deposited in both series. In films without Ti underlayers, good (001) textures were confirmed by X-ray diffraction and a peak (BH)_<max> of 20 MGOe was obtained for V_<Fe> of about 25%. In the series of films with Ti underlayers, coexistence of (001) and (101) textured grains was observed, while a maximum (BH)_<max> of 22 MGOe was obtained for V_<Fe> of about 6 %.