Magnetic properties and domain structures of FeNiMo/FeCoV double-layer films

Abstract

The presence of an FeNiMo underlayer (a few tens Å thick) with magnetic anisotropy between an FeCoV (a few thousands Å thick) and the substrate is found to change the magnetization process and reduce the coercive force of the FeCoV magnetic layer to about 3–10% of the original value with little reduction in saturation magnetization . This suppression of coercive force of the FeCoV layer does not occur when the FeNiMo is not present between the FeCoV layer and the substrate. The exact nature of the change in magnetic behavior of the FeCoV layer as well as the degree of reduction is found to be dependent on the existence and direction of magnetic anisotropy in the FeCoV magnetic layer upon deposition. The insertion of a non-magnetic Cu layer (100 Å thick) between the magnetic layers does not retard these effects, whereas the insertion of Si in a similar manner completely eliminates these effects. The results suggest that magnetic interaction between the magnetic anisotropy of these layers is responsible for these effects.