The intermediate valence of Ce in CeCo5 challenges standard density functional theory (DFT) and static DFT+U approaches, which fail to capture its magnetic properties. By combining DFT+U with exact diagonalization of the Anderson impurity model for the Ce 4f shell, we find a substantial reduction of Ce spin and orbital moments, consistent with DFT+DMFT, arising from Ce4+ - Ce3+ valence fluctuations. The total magnetic moment of 6.70 μB agrees with experiment, and the calculated 4f density of states reproduces photoemission and Bremsstrahlung isochromat spectra. The uniaxial magnetic anisotropy energy reaches 4.8 meV/f.u. when Coulomb correlations on both Ce 4f and Co 3d shells are included, in very good agreement with experimental data. These results highlight the importance of dynamical correlations and provide guidance for exploring high-performance, low-rare-earth-content permanent magnets.
@article{arxiv.2511.07063,
title = {Magnetic anisotropy and intermediate valence in CeCo$_5$ ferromagnet},
author = {Alexander B. Shick and Evgenia A. Tereshina-Chitrova},
journal= {arXiv preprint arXiv:2511.07063},
year = {2026}
}