| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rare earth-iron-boron magnet having a low coercive force and a high squareness ratio suitable for the magnet for a motor, and the production process of the same. <P>SOLUTION: The permanent magnet having a predetermined composition and a coercive force of not less than 0.5 kOe and not more than 3.5 kOe, and the squareness ratio represented by the ratio of the remnant magnetization to the magnetization in the magnetic field of 10 kOe is not less than 80%. The average recoil permeability in the second and third quadrant is 1.00-1.08. In a general formula (Ce<SB>1-x-y</SB>Nd<SB>x</SB>R<SB>y</SB>)<SB>a</SB>Fe<SB>b</SB>Co<SB>c</SB>B<SB>d</SB>M<SB>e</SB>X<SB>f</SB>, it is preferable that: R is at least 1 kind selected from Pr, Sm, Tb and Dy; M is at least 1 kind selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Ni and Cu; and X is at least 1 kind selected from Ga, Si and Al. <P>COPYRIGHT: (C)2010,JPO&INPIT |
