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. 12, 1989
Filed:
May. 09, 1988
Hideo Torii, Higashiosaka, JP;
Masaki Aoki, Minou, JP;
Hideaki Komoda, Hirakata, JP;
Nobuyuki Aoki, Hirakata, JP;
Ikuo Ota, Yawata, JP;
Keiichi Ochiai, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The present invention provides a platelike magnetic powder made from a magnetic powder having particles each of which has a portion comprising the spinel type crystal structure and a portion comprising the magnetoplumbite type crystal structure. The magnetic powder provides a large saturation magnetization .sigma.s and a small temperature change .DELTA.Hc/.DELTA.T of coercive force in the vicinity of the room temperature. Further, the present invention is to provide a high density magnetic recording medium which uses the magnetic powder. Furthermore, the present invention is to provide, a method to easily manufacture the magnetic powder by the coprecipitation method. A raw material powder of superfine particles is prepared. The prepared powder is fired at a low temperature in a non-oxidizing atmosphere.