Induced magnetic anisotropy and structure of nanocrystalline Fe-Co-Cu-Nb-Si-B alloys with different content of Co: I. Stress-annealing-induced magnetic anisotropy and its thermal stability

It is shown that the substitution of Co for Fe in the amorphous Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 alloy leads to the change in the type of magnetic anisotropy induced in the alloy as a result of a thermomechanical treatment at 520°C. The type of the induced magnetic anisotropy determines the functional characteristics of these alloys as soft magnetic materials. With the content of Co in the alloy equal to 10 at % Co, there is induced a magnetic anisotropy with the direction of the easy axis across the ribbon axis (transverse induced magnetic anisotropy), just as in the alloy without Co. Upon the introduction of 20–30 at % Co into the alloy, the induced magnetic anisotropy becomes longitudinal, with the easy-axis direction along the ribbon axis. The thermal stability of the magnetic properties of the alloys with induced magnetic anisotropy has been investigated.