Susceptibility and Mössbauer studies of magnetic rare earth-iron-silicides

Abstract

Ternary rare earth-iron-silicides of the Sc 2Fe 3Si 5 structure type have been studied by means of susceptibility measurements between 1.2 and 300 K and the Mössbauer effect at 4.2 K and room temperature. The compounds RE 2Fe 3Si 5 with RE = Gd—Er are antiferromagnetic with Néel temperatures below 11 K. Above 60 K, the susceptibilities follow a Curie- Weiss law with effective magnetic moments per RE atom approximately equal to the free ion values. 57Fe Mössbauer effect measurements of the above series and the superconductors forming with Sc, Y and Lu show quadrupole split spectra with small positive values of the isomer shift, indicating the absence of any magnetic moment at the iron site. There is no significant paramagnetic contribution to the 57Fe hyperfine field below the Néel temperature in the case of the antiferromagnetic compounds in applied fields up to 50 kG.