The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 1991
Filed:
May. 16, 1989
Applicant:
Inventors:
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01F / ;
U.S. Cl.
CPC ...
427132 ; 427251 ; 4272553 ;
Abstract
A magnetic recording medium comprising a substrate and, as a recording layer, a ferromagnetic metal thin layer formed on the substrate by deposition, in which the ferromagnetic metal thin layer contains oxygen atom in such a manner that concentrations of oxygen atom in a surface layer and an interfacial layer adjacent to the substrate are higher than that in an intermediate layer between the surface and interfacial layers, which has an improved coercive force and smaller magnetic domain.