First-Principles Calculations of Magnetite (Fe3O4) above the Verwey Temperature by Using Self-Consistent DFT plus U plus V
Abstract
In this report, we have used the DFT + U + V approach, an extension of the DFT + U approach that takes into account both on-site and intersite interactions, to simulate structural, magnetic, and electronic properties together with the Fe and O K-edge XAS spectra of Fe3O4 above the Verwey temperature (T-v). Moreover, we compared the simulated XAS spectra with experimental XAS data. We examined both orthogonalized and nonorthogonalized atomic orbital projectors and compared DFT + U + V to DFT, DFT + U, and HSE as a hybrid functional. It is noteworthy that, despite the widespread use of the same Hubbard U value for Fe-oct and Fe-tet at the DFT + U level in the literature, the HP code identified two distinct values for them using the Hubbard approaches (DFT + U and DFT + U + V). The resulting Hubbard U and V parameters are strongly dependent on the chosen orbital projectors. This study demonstrates how DFT + U + V can improve the structural, magnetic, and electronic properties of Fe3O4 compared to approximate DFT and DFT + U. In this context, DFT + U + V supports the half-metallic character of the bulk crystal Fe3O4 above T-v, since the Fermi level is found in the t(2g) band with a Fe-oct down-spin. Thus, the observations in the current study emphasize the significance of intersite interactions in the theoretical analysis of Fe3O4 above the T-v.
Más información
Título según WOS: | First-Principles Calculations of Magnetite (Fe3O4) above the Verwey Temperature by Using Self-Consistent DFT plus U plus V |
Título de la Revista: | JOURNAL OF CHEMICAL THEORY AND COMPUTATION |
Volumen: | 19 |
Número: | 23 |
Editorial: | AMER CHEMICAL SOC |
Fecha de publicación: | 2023 |
Página de inicio: | 8610 |
Página final: | 8623 |
DOI: |
10.1021/acs.jctc.3c00860 |
Notas: | ISI |