The electronic structure of rare-earth iron silicide R2Fe3Si5 superconductors

Abstract

The electronic structures of R 2 Fe 3 Si 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 E F in the 235-type Febased compounds is completely dominated by the Fe 3d states. Thus the different superconducting properties of some members of the R 2 Fe 3 Si 5 family are rather related to a presence of local magnetic moments of R-atoms than to electronic-structure features at E F .