Internally oxidized cobalt-rich amorphous alloys for potential magnetic recording media application

A new class of nanostructured magnetic materials which hold potential for novel recording media is described. Methods for minimizing intercrystalline interactions and reducing wear and corrosion by suitable coatings are obtained using the process of internal oxidation and crystallization of amorphous Co95.26−xFe4.74(BSi)x alloys. Such a process leads to solid state dispersions of single-domain isotropic cobalt particles coated with a borosilicate layer which provides compositional separation between the cobalt grains. ic microstructural differences were observed between samples of different metalloid compositions. The ribbons produced from compositions Co75.26Fe4.74Si2B18 and Co74.26Fe4.74Si13B8 proved to be the most promising for recording media application in terms of magnetic properties (coercivity 1200–1400 Oe) as well as morphological properties (size less than 300 Å). High coercivities obtained from these alloys are attributable to the increased surface anisotropy due to interactions between the Co particles and the borosilicate layer.