Effective anisotropy between magnetically soft and hard grains in nanocomposite magnets

摘要

Effect of grain size on the effective anisotropy constant between magnetically soft (α-Fe) and hard (Nd_2Fe_(14)B) grains in nanocomposite magnets, < K_(sh) >, has been investigated. The results show that the values of < K_(sh) > increase with decreasing size of soft grain, D_s, for the given size of hard grain, D_h. For the given D_s, < K_(sh) > increases with increasing D_h, and then approaches a steady value. In order to get a high value of < K_(sh) >, the hard grain size should be larger than 30 nm and the soft grain size should be about 10 nm.