Texture development and magnetic properties of sputter-deposited FePt-MgO nanocomposite films

We investigated the relationship among the development of out-of-plane magnetic anisotropy, the L 10 ordering reaction, and the texture development in multilayered (FePtMgO)n films that were sputter deposited on a Si substrate. A large out-of-plane coercivity (Hc) of about 9.8 kOe and a heteroepitaxially grown nearly perfect L 10 face-centered-tetragonal (001) texture were obtained for annealed (FePt 2.8 nmMgO 3.2 nm)6 films. The development of an L 10 FePt (002) texture, which is the primary condition for out-of-plane magnetic anisotropy, depends strongly on the degree of face-centered-cubic FePt (200) and MgO (200) texture development in the as-deposited state. The magnetic anisotropy of the FePt film could be controlled from in-plane to out-of-plane by varying the thickness of the FePt and MgO sublayers.