Patent ID: 6500277
Filing Date: 2002-12-31
Classification: B82Y,H01F,Y10S

Abstract:
A magnetic powder comprising:an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzSiw (where R is at least one rare-earth element, x is 8.1-9.4 at %, y is 0-0.30, z is 4.6-6.8 at %, and w is 0.2-3.0 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase; and the soft magnetic phase and the hard magnetic phase have a mean crystal grain size of 1-100 nm; wherein the magnetic powder has characteristics in which, when an isotropic bonded magnetic is molded by mixing the magnetic powder with a binding resin, a irreversible susceptibility (Xirr) is equal to or less than 5.0Ã—10âˆ’7 H/m; the irreversible susceptibility is measured by using a point where a demagnetization curve in a J-H diagram and a straight line that passes through the origin in the J-H diagram intersect; the demagnetization curve represents the magnetic characteristics at room temperature, and the straight line has a gradient (J/H) of âˆ’3.8Ã—10âˆ’6; and the intrinsic coercive force (Hcj) of the magnet at room temperature is in the range of 406-717 kA/m.