Soft-magnetic properties of microcrystalline Co-Fe-Si-B alloys prepared by sputtering

The magnetic and structural properties of microcrystalline Co-Fe-Si-B films prepared by sputtering were studied. This new soft-magnetic material exhibits a high rotational permeability of 1200 combined with a high saturation magnetization of 1.6 T. The soft-magnetic properties of this material can be explained by the fact that the thin film consists of fcc crystallites with a perfect < 111 > texture normal to the film plane. Because of this texture and the multiple twinning of the crystallites a six-fold symmetry and thus a small in-plane anisotropy are obtained. Any deviation from this structure and texture results in a material with a higher coercive force and a smaller permeability.