MAGNETIC-PROPERTIES AND MICROSTRUCTURE OF PERPENDICULAR MAGNETIC FE-ND SPUTTERED FILMS

The magnetic properties and microstructure in perpendicular magnetic films of Fe//1//0//0// minus //xNd//x (18 less than equivalent to x less than equivalent to 70) and (Fe//1// minus //yCo)//6//0Nd//4//0 (0 less than equivalent to y less than equivalent to 0. 25) alloys fabricated by rf sputtering are discussed. The intrinsic perpendicular magnetic anisotropy constant K//u in Fe-Nd and Fe-Co-Nd films becomes maximal at a temperature T//1 at which the magnetic anisotropy mode changes from the uniaxial to the cone-type as the temperature lowers. The T//1 increases with x in Fe-Nd and also the y in Fe-Co-Nd films. A high resolution electron microscopic observation reveals that some sort of a short range atomic ordering is present in the amorphous matrix in both the alloy systems, which gives rise to a lattice image. The origin of the perpendicular magnetic anisotropy is suggested to be associated with an anisotropic atomic arrangement in such structures.