イオンアシスト蒸着窒化鉄薄膜の磁気特性に及ぼす添加元素の影響

Abstract

Iron nitride films prepared by the ion-assisted vapor deposition method are promising for high density recording media because of their high coercivity. Their structure and magnetic properties were studied as a function of the contents of additive elements which were insoluble with iron such as Cu, Ag or Mg. Prepared films were characterized by VSM, XPS and Mössbauer spectroscopy. The coercivity of FeMgN films showed drastic decrease with the addition of only a small amount of Mg, while that of FeCuN and FeAgN remained nearly unchaged until the concentration of the additive elements reached a certain amount. XPS and Mössbauer studies showed that the nitrization of iron was suppressed only when Mg was chosen as the additive element, this is due to the selective nitrization of Mg in FeMgN films. It was concluded that the decrease in the coercivity of FeMgN was attributable to the decrease in the magnetic separation effect by the paramagnetic iron nitride phase, which presumably segregated along the column in FeN, FeCuN and FeAgN films.