EXCHANGE COUPLING AND COERCIVITY OF NANO CRYSTALLINE Nd4.5(Fe, Ga, Co)77.5B18 BONDED MAGNETS
纳米复合Nd4.5(Fe,Ga,Co)77.5B18磁体的矫顽力和交换耦合作用

The microstructure and coercivity of nanocomposite Nd4.5Fe76.5-xGaxCo1.0B18 (x=0- 0.6 (atomic fraction, %)) bonded magnets were studied. The results show that addition of small amount of Ga in Nd4.5Fe76.5-xGaxCo1.0B18 makes the grains finer and more uniform. A notable peak of coercivity was observed on the variation curve of coercivity with annealing time when Ga content is low (x=0.2). This phenomenon could be explained by the microstructure and the exchange coupling interaction of two-phase nanocomposite.