INVESTIGATION OF THE CRYSTAL PROPERTIES OF RFE2SI2 AND RFE2GE2 BY X-RAY-DIFFRACTION AND MOSSBAUER-SPECTROSCOPY

The RFe2Si2 and RFe2Ge2 intermetallic compounds, where R denotes a rare earth element, were investigated by X-ray diffraction and Mössbauer spectroscopy. The two series behave similarly in many respects. The values of lattice constants, isomer shift and quadrupole splitting vary gradually across the range of rare earths. Small deviations of the lattice constants of YbFe2Si2 and CeFe2Si2 compounds from the overall trend of the lattice parameters may indicate a non-trivalent state of ytterbium and cerium ions. The quadrupole splitting observed for both series reflects a deviation from the ideal tetrahedral coordination of iron-site neighbours. © 1990.