Affiliation:
1. Institute of Advanced Magnetic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310012, China
2. Guangdong Provincial Key Laboratory of Rare Earth Development and Application, Institute of Resources Utilization and Rare Earth Development, Guangdong Academy of Sciences, Guangzhou 510650, China
Abstract
Due to the rare earth supply shortage, ThMn12-type RFe12-based (R is the rare earth element) magnets with lean rare earth content are gaining more concern. Most ThMn12-type RFe12 structures are thermodynamically metastable and require doping of the stabilizing element Ti. However, the Ti-doping effects on the hard magnetic properties of RFe11Ti have not been thoroughly investigated. Herein, based on density functional theory calculations, we report the Ti-doping effects on the phase stability, intrinsic hard magnetic properties and electronic structures of RFe11Ti (R = La, Ce, Pr, Nd, Sm, Y, Zr). Our results indicate that Ti-doping not only increases their phase stability, but also enhances the magnetic hardness of ground-state RFe12 phases. Particularly, it leads to the transition of CeFe11Ti and PrFe11Ti from easy-plane to easy-axis anisotropy. Charge density distributions demonstrate that Ti-doping breaks the original symmetry of the R-site crystal field, which alters the magnetic anisotropy of RFe11Ti. Projected densities of states reveal that the addition of Ti results in the shift of occupied and unoccupied f-electron energy levels of rare earth elements, affecting their magnetic exchange. This study provides an insight into regulating the hard magnetic properties of RFe12-based magnets by Ti-doping.
Funder
National Science Fund for Distinguished Young Scholars
National Natural Science Foundation of China
Key R&D Projects of Zhejiang Province
National Key R&D Program of China
Basic and Applied Basic Research Foundation of Guangdong Province