Patent ID: 7169487

Claim:
A magnetic recording medium comprising a glass substrate having a principal surface on which at least a magnetic layer is formed, wherein: said glass substrate comprises an amorphous glass substrate, the principal surface of said amorphous glass substrate being provided with a texture having a predetermined surface roughness so that said magnetic layer is given circumferential magnetic anisotropy; said magnetic recording medium further comprising an AlRu alloy layer of a B2 crystal structure formed between said amorphous glass substrate and said magnetic layer and made of a material containing Al (aluminum) and Ru (ruthenium); said texture having a radial pitch equal to 0.005–0.05 μm, both inclusive, when said glass substrate is made of said amorphous glass substrate; said magnetic recording medium having an oriented ratio (OR) of 1.1 or more when said glass substrate is made of said amorphous glass substrate and when said AlRu alloy layer is of the B2 crystal structure, said oriented ratio (OR) being defined as a ratio of a magnetic characteristic in a circumferential direction to said magnetic characteristic in a radial direction, said magnetic characteristic being a coercive force (Hc).