title: Chemically Inhomogeneous RE-Fe-B Permanent Magnets with High Figure of Merit: Solution to Global Rare Earth Criticality.
abstract: The global rare earth (RE) criticality, especially for those closely-relied Nd/Pr/Dy/Tb in the 2:14:1-typed permanent magnets (PMs), has triggered tremendous attempts to develop new alternatives. Prospective candidates La/Ce with high abundance, however, cannot provide an equivalent performance due to inferior magnetic properties of (La/Ce)2Fe14B to Nd2Fe14B. Here we report high figure-of-merit La/Ce-rich RE-Fe-B PMs, where La/Ce are inhomogeneously distributed among the 2:14:1 phase. The resultant exchange coupling within an individual grain and magnetostatic interactions across grains ensure much superior performance to the La/Ce homogeneously distributed magnet. Maximum energy product (BH)max of 42.2 MGOe is achieved even with 36 wt. % La-Ce incorporation. The cost performance, (BH)max/cost, has been raised by 27.1% compared to a 48.9 MGOe La/Ce-free commercial magnet. The construction of chemical heterogeneity offers recipes to develop commercial-grade PMs using the less risky La/Ce, and also provides a promising solution to the REs availability constraints.
authors.affiliation: School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
authors.forename: Jiaying
authors.initials: J
authors.lastname: Jin
authors.affiliation: School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Ma
authors.affiliation: School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
authors.forename: Yujing
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Bai
authors.affiliation: School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Key Laboratory of Novel Materials for Information Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
authors.forename: Mi
authors.initials: M
authors.lastname: Yan