Surprising coercivity increment of sintered Ce-Fe-B magnets: Ce partly substituted by La

Aiming at refining the unideal microstructure and magnetic performance of sintered Ce-Fe-B magnets, La was introduced into the alloy. The role of La addition on the microstructure and magnetic properties revolution of Ce-Fe-B magnet was investigated in this study. The results suggested that La substitution could obstacle the phase structure deterioration during sintering process and maintained high 2:14:1 phase proportion. Meanwhile, uniform grain size and continuous RE-rich grain boundary phase appeared with La addition, which could be attributed to the segregation behaviors of La element and enhanced oxidation resistance with more 2:14:1 phase. The coercivity showed noteworthy increase from 2.93 kOe to 4.78 kOe under the synergetic effect of maintained 2:14:1 phase proportion, uniform RE(2)Fe14B grain and even RE-rich phase distribution. This work indicated that La could act as a useful additive to obtain the cost-effective magnetic materials with moderate performance.