HIGH-FIELD HYSTERESIS LOOP OF ND-FE-B MAGNET AND RELATED MATERIALS

Magnetization measurements were made on single crystals of (Nd//1// minus //xDy//x)//2Fe//1//4B and sintered materials of (Nd//1// minus //xDy//x)//1//5Fe//7//7B//8 with x equals 0. 33, 0. 47 and 0. 60, in high magnetic fields up to 15 T and at temperatures 4. 2-320 K. The magnetization of the single crystals is not saturated in difficult directions even at 15 T, and no hysteresis is observed in the easy direction except at 4. 2 K. The sintered materials aligned by a magnetic field before sintering exhibit a remarkable hysteresis loop, the coercive field amounting to 11 T at 4. 2 K. The coercivity of the sintered materials is related to the anisotropy of the single crystals with corresponding values of x.