MAGNETIC-PROPERTIES OF FE-CO NITRIDE THIN-FILMS II

In the previous paper, it was reported that the addition of Co to Fe-N films prepared by the ion-assisted vapor deposition method (IVD) with oblique incidence of metal vapor to the substrate could increase their saturation magnetization without deteriorating their superior corrosion-resistance. In this paper the magnetic properties of Fe-Co nitride thin films prepared by the IVD method with normal incidence of metal vapor were investigated. A suitable amount of Co added to the Fe-N films could improve the perpendicular magnetic properties. The highest Hk and Hc, 4.2 kOe and 600 Oe respectively, were obtained at the Co addition of nearly 25 at.%. The improvement could be attributed to the change of the distribution of nitride phases inside each column, which would have an effect on the magnetic separation of ferromagnetic Fe-Co alloy phase from neighboring phases. The saturation magnetization changed with the Co addition, roughly following the Slater-Pauling curve. This was attributable to the change of magnetic moment in the Fe-Co alloy cluster. © 1990 IEEE