Showa Denko Kabushiki Kaisha

Showa Denko K.k.

Hiroshi Kanazawa

Hiroshi Sakai

Kazunori Ohnami

Mikio Suzuki

Hiroshi Ohsawa

Kazunori Onami

The present invention relates to a magnetic recording medium, which has excellent magnetic characteristics. The present invention also relates to a method for producing a magnetic recording medium where a plurality of targets are repeatedly sputtered several times in sequential order to form non-magnetic and magnetic films on a substrate.

Magnetic recording medium and production process thereof

A magnetic recording medium comprising a non-magnetic substrate having thereon a non-magnetic undercoat, a magnetic film and optionally a protective film. The magnetic film comprises a material containing Co as a main component. The non-magnetic undercoat comprises at least two layers including a first undercoat film and a second undercoat film provided on the first undercoat film. The first undercoat film comprises a material containing Cr as a main component, and the second undercoat film comprises a material selected from the group consisting of a Cr/Nb-base alloy, a Cr/W-base alloy, a Cr/V-base alloy and a Cr/Mo-base alloy as a main component.

Magnetic recording medium

A low noise magnetic recording medium having a high coercive force and adapted for use with a MR head. The magnetic recording medium comprises a non-magnetic substrate having thereon a first non-magnetic underlayer and a magnetic layer comprising a Co alloy provided on the non-magnetic underlayer. The non-magnetic underlayer comprises an alloy represented by the formula: (Ni,Al),M,, wherein M is one of Cr (X&equals;1-40 at %), Mo (X&equals;1-50 at %), W (X&equals;1-60 at %), V (X&equals;1-35 at %), Zr (X&equals;1-25 at %), Nb (X&equals;1-35 at %) and Pd (X&equals;1-25 at %), and when M includes two or more of Cr, Mo, W, V, Zr, Nb and Pd, X is from 1 to 60 at %.

Magnetic recording medium, non-magnetic alloy film and sputtering target

A magnetic recording medium having sufficiently low noise and high coercive force suitable for use with a MR head. The magnetic recording medium comprises a non-magnetic substrate 1, a non-magnetic underlayer 2, a magnetic layer 3 and a protective layer 4. The magnetic layer comprises a Co alloy and the non-magnetic underlayer comprises a first underlayer 21 comprising an Al--Co--Ni alloy and a second underlayer 22 comprising Cr or a Cr alloy laminated on the first underlayer.

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Chiba, Japan

Hiroshi Kanazawa