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:
Jul. 13, 2004
Filed:
Feb. 15, 2002
Applicant:
Inventors:
Assignee:
Ugimag S.A., Saint Pierre d'Allevard, FR;
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/706 ; H01F 1/11 ; H01F 1/34 ; H01F 1/36 ;
U.S. Cl.
CPC ...
G11B 5/706 ; H01F 1/11 ; H01F 1/34 ; H01F 1/36 ;
Abstract
A method for manufacturing type M hexaferrite powders fo the formula AFe O where A is Ba, Sr, Ca, Pb or a mixture thereof. An iron oxide Fe O and a compound A are mixed with a molar ratio n=Fe O /AO, formed and calcined, and the agglomerates which result from the calcining are ground to obtain a fine ferrite powder. The mixture is formed with a ratio n ranging between 5.7 and 6.1, and with a predetermined degree of homogeneity, and before or during the grinding process, an agent controlling the microstructure is introduced.