Microstructure and magnetic properties of Nd_(2)Fe_(14)B/3:29 phase and Nd_(2)Fe_(14)B/SmCo nanocomposite permanent magnets

摘要

The microstructure and magnetic properties of nanocomposite magnets prepared from ball-milled powders of Nd-Fe-B nanocrystalline melt-spun ribbons and Nd_(9.375)Fe_(59.0625)Co_(25.3125)Ti_(6.25) (3:29 phase) or Sm_(11.114)(Co_(65.777)Fe_(8.888)Cu_(10.666)Zr_(3.555))_(8) melt-spun ribbons have been investigated. The nucleation field exceeds the coercive field, indicating strong exchange coupling between the grains for NdFeB/3:29 nanocomposites. The magnetostatic interactions are predominant for 10 wt.percent Sm-Co-based powders, whilst for higher contents the exchange interactions are much stronger, the maximum being reached for 15 wt.percent Sm-Co powders. The Curie temperature also increases with 72 deg C compared with NdFeB powders.