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:
Feb. 16, 1988
Filed:
Dec. 24, 1984
Tomohisa Komoda, Nara, JP;
Mamoru Ishizuka, Nara, JP;
Shuhei Tsuchimoto, Nara, JP;
Mitsuhiko Yoshikawa, Ikoma, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A Co-Cr perpendicular magnetic recording medium includes a chromium oxide film formed on a Co-Cr perpendicular magnetization film, and a SiO.sub.2 protective film formed on the chromium oxide film. The chromium oxide film is formed by conducting a heating treatment to the surface of the Co-Cr perpendicular magnetization film in an oxygen atmosphere of about 10.sup.-4 to 10.sup.-3 Torr, at a temperature of about 300.degree. C. to 400.degree. C. for about two hours. The chromium oxide film has a thickness of about 20 to 200 .ANG.. The SiO.sub.2 protective film has a thickness greater than 50 .ANG., but the total thickness of the chromium oxide film and the SiO.sub.2 protective film is selected between 70 and 300 .ANG..