title: Manipulating Ce Valence in RE2Fe14B Tetragonal Compounds by La-Ce Co-doping: Resultant Crystallographic and Magnetic Anomaly.
abstract: Abundant and low-cost Ce has attracted considerable interest as a prospective alternative for those critically relied Nd/Pr/Dy/Tb in the 2:14:1-type permanent magnets. The (Nd, Ce)2Fe14B compound with inferior intrinsic magnetic properties to Nd2Fe14B, however, cannot provide an equivalent magnetic performance. Since Ce valence is sensitive to local steric environment, manipulating it towards the favorable trivalent state provides a way to enhance the magnetic properties. Here we report that such a desirable Ce valence can be induced by La-Ce co-doping into [(Pr, Nd)1-x(La, Ce)x]2.14Fe14B (0 ≤ x ≤ 0.5) compounds via strip casting. As verified by X-ray photoelectron spectroscopy results, Ce valence shifts towards the magnetically favorable Ce(3+) state in the composition range of x > 0.3, owing to the co-doping of large radius La(3+) into 2:14:1 phase lattice. As a result, both crystallographic and magnetic anomalies are observed in the same vicinity of x = 0.3, above which lattice parameters a and c, and saturation magnetization Ms increase simultaneously. Over the whole doping range, 2:14:1 tetragonal structure forms and keeps stable even at 1250 K. This finding may shed light on obtaining a favorable Ce valence via La-Ce co-doping, thus maintaining the intrinsic magnetic properties of 2:14:1-type permanent magnets.
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: 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: Zeyu
authors.initials: Z
authors.lastname: Qian
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: Chen
authors.initials: C
authors.lastname: Wu
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: State Key Laboratory for Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Baogen
authors.initials: B
authors.lastname: Shen
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