Abstract
Abstract
Magneto-crystalline anisotropies, K
u
, and anisotropic magnetic fields, H
a
, of two rare-earth (RE) magnets, i.e. CeFe12, and PrFe12, are theoretically calculated by using the crystal field (CF) method based on the first principles density functional theory (DFT) and the non-collinear DFT + U (NCDFT + U) method. The CF method reproduces an experimental H
a
of PrFe12 but it failed to reproduce the H
a
of CeFe12, providing H
a
with a wrong sign. The NCDFT + U method correctly reproduces experimental H
a
of CeFe12 and PrFe12, however the optimization of effective Hubbard on-site interaction parameters, U
eff
, of the 4f electrons of the magnets is indispensable for the accurate calculation of H
a
. We have found that the CF method is valid in so far as it is used for the study of K
u
of RE magnets, which have RE atoms heavier than Pr atom. We expect that the NCDFT + U method would become a quantitative K
u
calculation method of any RE magnets if the U
eff
calculation method of 4f electrons of RE magnets is established.
Subject
General Physics and Astronomy