Victor Company of Japan, Limited

Toshio Kato

Shigeo Shimizu

Toshikazu Nishihara

Akihiro Kimura

Hitoshi Oda

Masanobu Shigeta

Toshiro Abe

Makoto Mizukami

Toshio Ando

Masaki Shintani

Kanji Takashima

Koichiro Yamazki

A magnetic recording medium which comprises a non-ferromagnetic substrate having two types of defects or irregularities formed thereon along a circumferential direction with different center line average roughnesses, on which a non-ferromagnetic metal film and a Co alloy ferromagnetic film are formed by sputtering in this order. The ferromagnetic film has such a crystal structure that a (200) plane is parallel to the surface of the substrate and a &lt;011&gt; orientation is toward a circumferential direction. Thus, the C axis of the ferromagnetic film is oriented toward the circumferential direction of the substrate. A method for fabricating the magnetic recording medium is also described wherein the distance between the substrate and the respective targets for the non-ferromagnetic metal film and the Cr alloy ferromagnetic film is set within a mean free path of sputtered particles and the substrate is heated to a temperature of from 150.degree. to 300.degree. C. when these films are formed by sputtering.

Magnetic recording medium

A magnetic recording medium for high density recording comprising a non-magnetic substrate, a Cr undercoat and a magnetic Ni-Cr-Co alloy thin layer formed on the substrate. The magnetic alloy thin layer has a thickness of from 400 to 1200 angstrom and a Cr content of from 3 to 17 atomic percent. As a result, improved magnetic characteristics and corrosion resistance of the medium are ensured.

Magnetic recording medium comprising a magnetic Co-Ni-Cr alloy thin layer

A magnetic recording medium of the type which comprises a non-magnetic support, and a thin magnetic metal layer formed on at least one surface of the support is described. The magnetic metal layer is protected with a carbon nitride layer.

Magnetic recording medium comprising a protective carbon nitride layer

A magnetic recording medium comprising a support, a first layer formed on the support by evaporating cobalt or its alloy by an oblique-incidence vacuum evaporation technique, and a second plated layer made of cobalt or its alloy and formed by a wet plating. The cobalt alloy for the first layer substantially consists of, aside from cobalt, up to 30 wt % of Ni, Fe, Cu, W, Cr, Ru or a mixture thereof. On the other hand, the cobalt alloy for the second layer substantially consists of up to 40 wt % of Ni, up to 8 wt % of P and the balance of Co.

Magnetic recording media suitable for use in vertical magnetization recording systems are described. The media comprise a magnetic layer on at least one side of a substrate. The magnetic layer is made of a specific type of quaternary alloy. The alloy essentially consists of from 3 to 42 wt % of Co, from 54 to 89 wt % of Ni, from 4 to 8 wt % of P, and from 0.1 to 3.2 wt % of Zn provided that (7.2 X.sub.P +12.8) wt %.ltoreq.X.sub.Ni .ltoreq.(7.2 X.sub.P +43.2) wt % in which X.sub.P represents a content of P and X.sub.Ni represents a content of Ni, both expressed by wt %.

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Yamato, Japan

Toshio Kato