SrM薄膜における磁気特性のターゲット組成依存性  [in Japanese] Dependence of the Magnetic Properties of Sr Ferrite Films on the Compositional Ratio of the Target  [in Japanese]

Hexagonal strontium ferrite (SrM, SrFe_<12>O_<19>) thin films were deposited by dc sputtering with a target composition ratio N (the ratio of Fe/Sr in SrFe_NO_X) in the range of 8 to 14. It was found that the target composition N necessary for the preparation of SrM films with a stoichiometric composition is around 9. Preferential orientation of the c-axis in films deposited at a substrate temperature of 600 ℃ was observed most strikingly for films prepared with a target composition of around 9. The saturation magnetization and coercivity in the perpendicular direction were about 260 emu/cc and 3.5 kOe, respectively, when the film was prepared with a target composition ratio N of 8. The surface grain size observed by scanning electron microscope was about 150nm.