Magnetic recording medium

Claim 1

A magnetic recording medium comprising: (A) a non-magnetic substrate disk; (B) at least one magnetic layer; and (C) at least one protective layer; said magnetic layer (B) and said protective layer (C) being formed in succession on the non-magnetic substrate disk (A), wherein the non-magnetic substrate disk (A) comprises (1) a glass substrate having a smooth surface, and (2) at least one electrically conductive non-magnetic metallic film provided on a surface of the glass substrate by vapor deposition or sputtering in vacuum, said electrically conductive non-magnetic metallic film (A) (2) having a thickness in the range of not less than 0.03 μm and not more than 5 μm, and being provided on a surface thereof with a multitude of fine concentric grooves by texturing treatment of said surface of the electrically conductive non-magnetic metallic film (A) (2); wherein the magnetic layer (B), which is provided on the surface of the electrically conductive non-magnetic metallic film (A) (2), comprises (1) a sublayer which is a film of Cr, W or Mo or a film of an alloy consisting essentially of Cr, W or Mo, said sublayer (B) (2) being formed by vapor deposition or sputtering in vacuum; and (b 2) a main magnetic layer which is a film of Co or a film of an alloy consisting essentially of Co, said main magnetic layer (B) (2) being formed by vapor deposition or sputtering in vacuum on the sublayer (B) (1); and wherein said protective layer (C) is provided on the main magnetic layer (B) (2).