Magnetic Properties of Y-Fe-B system Alloys

The results of studies on the relation between the microstructure and magnetic properties of Y-Fe-B system alloys which were first quenched and then annealed are reported. A coercive force of 6 kOe and saturation magnetic moment of 61 emu/g were obtained for an Y16Fe76B8 sample with annealing at 700°C for one hour. Aging at 660°C brought about increases in both coercivity and saturation magnetic moment up to one hour, after which these deteriorated; X-ray diffraction studies indicated the presence of an unknown ¿ phase, which grew with the aging time and was inferred to be the cause of the deterioration.