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:
May. 22, 1979
Filed:
Mar. 03, 1977
Seizi Hattori, Ibaragi, JP;
Takehiko Nakagawa, Kawasaki, JP;
Kazuo Kobayashi, Ayasemachi, JP;
Koichi Makino, Yokohama, JP;
Wakatake Matsuda, Zama, JP;
Fujitsu Limited, BOTH OF, JP;
Nippon Telegraph & Telephone Public Corporation, BOTH OF, JP;
Abstract
A thin film of ferrite for use as a magnetic recording medium contain (a) Cu, (b) both Cu and Co, or (c) Cu, Co and Nb. The inclusion of Cu increases the temperature range for reduction from .alpha.-Fe.sub.2 O.sub.3 to one of the ferrites, i.e. Fe.sub.3 O.sub.4, and also lowers the above-mentioned reducting temperature. The addition of Co improves the magnetic properties of the ferrite. The simultaneous addition of Cu, Co and Nb provides .gamma.-Fe.sub.2 O.sub.3 with excellent magnetic properties, which are stable over wide temperature range for oxidizing the Fe.sub.3 O.sub.4 to the .gamma.-Fe.sub.2 O.sub.3.