Magnetic Anisotropy of Rate-Earth-Cobalt Films Prepared with In-Plane Magnetic Field

Tb-FeCo, Dy-Co and Gd-Co amorphous films were prepared using a DC sputtering apparatus with in-plane magnetic field of 15 Oe or 3 KOe. In Tb-FeCo films, in-plane uniaxial magnetic anisotropy with an easy axis parallel to in-plane field was induced in addition to perpendicular uniaxial anisotropy. In-plane uniaxial anisotropy increased at a cost of perpendicular uniaxial anistoropy with a decrease in Tb content. Although smaller in-plane anisotropy was induced in Dy-Co films, no in-plane anisotropy was induced in Gd-Co films. Tb-Co films were also prepared using a plannar-magnetron sputtering apparatus with or without in-plane field of 3 kOe. In-plane uniaxial anisotropy was induced only when in-plane field was applied. These results suggest that the application of in-plane field causes an anisotropic arrangement of atoms in the film plane, which induces in-plane uniaxial anisotropy through single-ion anisotropy of rare earth atoms