Patent Number: 6,761,830

Title: Method for making m- type hexaferrite powders or wafers

Abstract: A method for manufacturing type M hexaferrite powders fo the formula AFe.sub.12 O.sub.19 where A is Ba, Sr, Ca, Pb or a mixture thereof. An iron oxide Fe.sub.2 O.sub.3 and a compound A are mixed with a molar ratio n=Fe.sub.2 O.sub.3 /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.

Inventors: Morel; Antoine (Evreux, FR), Brando; Eric (Laredo, TX), Tenaud; Philippe (Bernin, FR)

Assignee: Ugimag S.A.

International Classification: C04B 35/26 (20060101); C01G 49/00 (20060101); H01F 1/032 (20060101); G11B 5/706 (20060101); H01F 1/11 (20060101); G11B 005/706 (); H01F 001/11 (); H01F 001/34 (); H01F 001/36 ()

Expiration Date: 07/12012