Magnetic disk having improved surface configuration and magnetic disk unit including same

U.S. Patent Number: 5388020

Abstract: There is disclosed a magnetic disk having a surface shape so designed as to satisfy flying characteristics and sliding characteristics in CSS and the head adhesion even in a high-density recording. The surface shape of the contact surface of the magnetic disk for contact with a sliding surface of a magnetic head plays a very important role in the magnetic disk characteristics such as the head flying characteristics, the head adhesion and the CSS characteristics, and it has been found that a three-dimensional load ratio (0.5% to 10%) and a symmetric property Rsk (0.5 to 2) of a cross-section curve representing depressions and projections on the surface are essential as items of evaluation of this surface shape. For example, the surface shape of an aluminum alloy disk plated with Ni-P is processed in such a manner that the load ratio of the three-dimensional load ratio BR5 is 0.5% to 10% and that the symmetric property Rsk of the cross-sectional shape of this surface is 0.5 to 2. Then, a chromium intermediate film, a Co-Cr magnetic film, a carbon protective film and a film of lubricant are formed on the substrate. By doing so, the magnetic disk having the desired characteristics can be obtained.

Inventors: Nakamura; Takao (Yokohama, JP), Sekiyama; Nobuya (Yokohama, JP), Tani; Hiroshi (Atsugi, JP), Kato; Yoshiki (Tokyo, JP)

Assignee: Hitachi, Ltd. (Tokyo, JP)

Application Number: 07/964,897

Issued: 1995-02-07

Expired: 2007-02-07

Classes: 360/135 ; 428/141; 428/848.2

Field of search: 360/135,103,133 428/694TR,694SG,64,141 427/128,129

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