Patent ID: 7465409
Filing Date: 2008-12-16
Classification: C04B,G03G,H01F

Abstract:
1. A method of forming hard magnetic core particles comprising: combining at least one ferric oxide, at least one strontium oxide precursor, at least one oxygenated boron compound, and at least one binder to form a mixture, wherein said strontium oxide precursor is present in an amount that provides SrO in a molar amount that is in excess of a stoichiometric amount that provides a ratio of Fe forming the mixture into green beads, and firing the green beads to form said hard magnetic core particles, wherein said mixture contains an amount of said strontium oxide precursor that provides about 5 to about 30 mole % excess of SrO and wherein said mixture contains said oxygenated boron compound in an amount that provides B