The electronic structure of rare-earth iron silicide superconductors

摘要

The electronic structures of R_2Fe_3Si_5 (where R = Lu, Tm, Er, Tb, Yb) intermetallics have been calculated from first principles in local-spin density (LSDA) and LSDA + U approaches. The majority of rare-earth iron silicides, except for the heavy-fermion Yb-based compound, exhibit almost equal values of density of states at the Fermi level (E_F) as well as very similar Fermi surface topology. The electronic structure around Ep in the 235-type Fe-based compounds is completely dominated by the Fe 3d states. Thus the different superconducting properties of some members of the R_2Fe_3Si_5 family are rather related to a presence of local magnetic moments of R-atoms than to electronic-structure features at E_F.