Patent ID: 7172642

Claim:
Magnetic metal particles containing iron as a main component, comprising cobalt in an amount of 20 to 50 atm %, calculated as Co, based on whole Fe, aluminum in an amount of 3 to 15 atm %, calculated as Al, based on whole Fe and a rare earth element in an amount of 3 to 20 atm %, calculated as rare earth element, based on whole Fe, and having an average major axis diameter of 0.02 to 0.065 Î¼m, a crystallite size D 110 of 90 to 150 â„«, a coercive force of 159.2 to 222.9 kA/m (2,000 to 2,800 Oe), a soluble Na content of not more than 20 ppm, a soluble Ca content of not more than 100 ppm, a sulfur content of not more than 60 ppm, and an oxidation stability Î”Ïƒs of not more than 8%.