Abstract
Identifying the dopants and their occupation sites in rare-earth-doped permanent magnets is critical not only to understand the mechanism of tuning their magnetic properties, but also to develop guiding principles to further improve their performance. In this study, we present a direct observation of the preferred atomic sites of La atoms in La-doped M-type SrFe12O19 hexaferrite. Our data solidly clarified that only the Sr2+ cations were replaced by La3+ cations, and the La-doping caused the changes in the valence states of iron cations located at the 4f1 and 2a crystallographic sites. First principles calculations further revealed that after La-doping, the changes in the spin states of the Fe3+ cations located at the 4f1 tetrahedral sites resulted in magnetization enhancement and those of the 2a octahedral sites contributed to electrical neutrality, well matching the experimental atomic-column resolution EELS and magnetic measurement results.
Original language | English (US) |
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Pages (from-to) | 4385-4393 |
Number of pages | 9 |
Journal | Nanoscale |
Volume | 11 |
Issue number | 10 |
DOIs | |
State | Published - 2019 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This work was supported by National Natural Science Foundation of China (51771085, 51571104, 51801087, 51801088 and 11274145) and Open Project of Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University (LZUMMM2018003, LZUMMM2018012 and LZUMMM2019008).