| 摘要 |
PROBLEM TO BE SOLVED: To improve an anisotropy constant, residual magnetic flux density an the maximum energy product by a method wherein a Y-containing rare-earth element, B and Fe are brought in the atomic % within the value of the specific range, the main phase is composed of a tetragonal phase, and this material has the maximum energy product higher than the specific value in the ultra-low temperature zone lower than the specific temperature value. SOLUTION: A rare-earth element R occupies 10 to 30 atomic % of the composition of the magnet material, at least 80% or more of the R consists of Pr and Nd, and 40% or more of R consists of Pr. B should be in the range of 2 to 28 atomic %. Fe of 65 to 80 atomic % should be contained. This permanent magnet indicates the coercive force of iHc 10kOe in the ultra-low temperature zone of 150K or lower and the residual magnetic flux density of Br>11kG, and also indicates the maximum energy product (BH)max of 40MGOe or higher. As above-mentioned, an anisotropic factor, residual magnetic flux density and maximum energy product can be improved remarkably. |
