Phase stability and coercivity in La2Fe14B magnet
Critical rare-earth free La2Fe14B (2:14:1) has the potential to be a gap permanent magnet. However, La2Fe14B decomposes into La, α-Fe, and LaFe4B4 phases below 1067 K. The phase stability and coercivity have been studied in La2Fe14B magnet using first principles DFT (density functional theory) calcu...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2023-02-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/9.0000403 |
| _version_ | 1811154899656769536 |
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| author | X. B. Liu I. C. Nlebedim |
| author_facet | X. B. Liu I. C. Nlebedim |
| author_sort | X. B. Liu |
| collection | DOAJ |
| description | Critical rare-earth free La2Fe14B (2:14:1) has the potential to be a gap permanent magnet. However, La2Fe14B decomposes into La, α-Fe, and LaFe4B4 phases below 1067 K. The phase stability and coercivity have been studied in La2Fe14B magnet using first principles DFT (density functional theory) calculation and micromagnetic simulation. For a perfect La2Fe14 B cube (edge length of 256 nm) without any structural defects and soft magnetic secondary phases, the coercivity (8.5 kOe) is reduced to ∼40% of its magnetocrystalline anisotropy field (HA = 20 kOe). Further, the coercivity sharply reduces to 3.2 kOe upon forming a thin layer (2 nm) of α-Fe on the surface of the La2Fe14B cube particle. The DFT calculations indicate that a partial replacement of La by other rare-earth (RE) elements can enhance the structural stability of 2:14:1. The gains in cohesive energy are 0.75, 0.10, and 0.33 eV per formula unit in (La0.5RE0.5)2Fe14B with RE = Ce, Pr, and Nd, respectively. Stabilizing the 2:14:1 structure and mitigating the formation of soft magnetic structural defects or impurity phases such as α-Fe is necessary to develop La2Fe14B based magnet, which can be moderately achieved via partial substitution of La by other rare earth elements such as Ce, Pr, and Nd. |
| first_indexed | 2024-04-10T04:23:45Z |
| format | Article |
| id | doaj.art-4f2390699099465f8f495f6a48a0770b |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-10T04:23:45Z |
| publishDate | 2023-02-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-4f2390699099465f8f495f6a48a0770b2023-03-10T17:26:21ZengAIP Publishing LLCAIP Advances2158-32262023-02-01132025211025211-510.1063/9.0000403Phase stability and coercivity in La2Fe14B magnetX. B. Liu0I. C. Nlebedim1Critical Materials Institute, Ames National Laboratory of US DOE, Ames, Iowa 50011, USACritical Materials Institute, Ames National Laboratory of US DOE, Ames, Iowa 50011, USACritical rare-earth free La2Fe14B (2:14:1) has the potential to be a gap permanent magnet. However, La2Fe14B decomposes into La, α-Fe, and LaFe4B4 phases below 1067 K. The phase stability and coercivity have been studied in La2Fe14B magnet using first principles DFT (density functional theory) calculation and micromagnetic simulation. For a perfect La2Fe14 B cube (edge length of 256 nm) without any structural defects and soft magnetic secondary phases, the coercivity (8.5 kOe) is reduced to ∼40% of its magnetocrystalline anisotropy field (HA = 20 kOe). Further, the coercivity sharply reduces to 3.2 kOe upon forming a thin layer (2 nm) of α-Fe on the surface of the La2Fe14B cube particle. The DFT calculations indicate that a partial replacement of La by other rare-earth (RE) elements can enhance the structural stability of 2:14:1. The gains in cohesive energy are 0.75, 0.10, and 0.33 eV per formula unit in (La0.5RE0.5)2Fe14B with RE = Ce, Pr, and Nd, respectively. Stabilizing the 2:14:1 structure and mitigating the formation of soft magnetic structural defects or impurity phases such as α-Fe is necessary to develop La2Fe14B based magnet, which can be moderately achieved via partial substitution of La by other rare earth elements such as Ce, Pr, and Nd.http://dx.doi.org/10.1063/9.0000403 |
| spellingShingle | X. B. Liu I. C. Nlebedim Phase stability and coercivity in La2Fe14B magnet AIP Advances |
| title | Phase stability and coercivity in La2Fe14B magnet |
| title_full | Phase stability and coercivity in La2Fe14B magnet |
| title_fullStr | Phase stability and coercivity in La2Fe14B magnet |
| title_full_unstemmed | Phase stability and coercivity in La2Fe14B magnet |
| title_short | Phase stability and coercivity in La2Fe14B magnet |
| title_sort | phase stability and coercivity in la2fe14b magnet |
| url | http://dx.doi.org/10.1063/9.0000403 |
| work_keys_str_mv | AT xbliu phasestabilityandcoercivityinla2fe14bmagnet AT icnlebedim phasestabilityandcoercivityinla2fe14bmagnet |