Synthesis and Crystal Structure of Er₆Fe_17.66Al_5.34C_0.65 Intermetallic Compound

Abstract

A new quaternary carbide, Er₆Fe_17.66Al_5.34C_0.65, was isolated in the course of an investigation of a continuous solid solution Er₆Fe_23-xAl_x. The crystal structure of Er₆Fe_17.66Al_5.34C_0.65 was refined from single-crystal X-ray diffraction data collected at room temperature. Er₆Fe_17.66Al_5.34C_0.65 crystallizes in the space group Fm-3m with a unit-cell parameter a = 12.1273(6)Å. The structure may be regarded as the filled Th₆Mn₂₃ structure-type, where [Er₆Fe_16.6Al_5.4] form a three-dimensional network delimiting two octahedral voids centered at the iron (4b crystallographic site) and carbon (4a crystallographic site) atoms. Al atoms substitute only Fe atoms located at the 32f crystallographic site.