Structural, thermal and magnetic properties of Y2Fe2Si2C

We report detailed investigations on the structural, thermal and magnetic properties of Y2Fe2Si2C over the temperature range 2–300 K using x-ray diffraction, specific heat, 57Fe Mössbauer spectroscopy and first-principles calculations. Low temperature measurements show no pronounced anomalies which might signal magnetic ordering of the Fe sublattice at low temperature. Analyses of the specific heat data of Y2Fe2Si2C reveal the presence of a localised Einstein mode, suggesting the importance of an optical contribution to the phonon spectrum of Y2Fe2Si2C. Based on electronic structure calculations, we found a low density of states of the Fe 3d bands at the Fermi level. The corresponding density of states are below the Stoner criterion, thus indicating a non-magnetic state of the Fe atoms in Y2Fe2Si2C, in agreement with the experimental findings.