Superconductivity and magnetism in the series R sub 2 Fe sub 3 Si sub 5 by Moessbauer and magnetization measurements

Members of the R2Fe3Si5 series become either superconducting or magnetically ordered depending on whether the metal atom R (= rare earth, Y or Sc) is diamagnetic or paramagnetic respectively. Moessbauer effect and magnetization measurements were made to determine the magnetic state of the iron and the nature of the superconducting electrons. Iron 57 Moessbauer measurements on the Sc, Dy and Er compounds all showed two partially resolved, quadrupole split spectra at all temperatures from 300 to 1.5 K, indicating that there is no resolvable magnetic interaction at the iron site. The nature of the superconducting electrons in the series is discussed in the light of available measurements.