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:
Dec. 07, 1976
Filed:
May. 26, 1972
Shih-Lu Chen, Painted Post, NY (US);
James A Murphy, Painted Post, NY (US);
Corning Glass Works, Corning, NY (US);
Abstract
A method of increasing the coercivity of a magnetic device having a magnetite film reduced from alpha ferric oxide. The alpha ferric oxide film is reduced to magnetite by subjecting it to a temperature greater than 400.degree. C in a reducing atmosphere. The temperature of the film is then changed to between about 150.degree. and 300.degree. C, and the reducing atmosphere is replaced by an oxidizing atmosphere. The film is subjected to the oxidizing atmosphere while the temperature is held between 150.degree. and 300.degree. C, thus causing the magnetite film to become partially oxidized to form a solid solution of magnetite and gamma ferric oxide as represented by the formula, (1-x)Fe.sub.3 O.sub.4 .sup.. xFe.sub.2 O.sub.3, where x is between 0.49 and 0.85.