Upper critical fields in RE2Fe3Si5 (RE=Y, Sc, Lu) compounds

Abstract
The RE2Fe3Si5 compounds form with RE=Sm, Gd to Lu, Sc and Y and crystallize in the tetragonal Sc2Fe3Si5‐type structure. The compounds with RE=Lu, Y, and Sc are superconducting while those with RE=Gd to Er are antiferromagnetically ordered. We have carried out upper critical field (Hc2) measurements on Y2Fe3Si5, Sc2Fe3Si5 and Lu2Fe3Si5. The Lu compound, with the zero field Tc of 6.0 K, has Hc2(0)=60 kOe, which is the highest for an iron‐containing ternary compound. The results of critical field measurements have been analyzed in terms of WHH theory.