Abstract
Highly aligned SmFe12/α-Fe nanocomposite thin films were fabricated by rf magnetron sputtering onto heated glass substrates. The volume fraction of the α-Fe phase (VFe) was adjusted systematically by putting a different number of Sm tips (5 × 5 mm2) on the Fe target. Nearly single-phase SmFe12 films of ThMn12-type structure with the (001) plane aligned parallel to the film plane were synthesized at a substrate temperature Ts of 550°C by using 28 Sm tips. These films exhibited good squareness in the demagnetization curve. By reducing the number of Sm tips to 12 and keeping the substrate temperature Ts at 550°C, we fabricated nanocomposite films with different VFe’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 VFe 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 VFe of about 6%.
