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 Fe[Formula: see text]B 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.