Ternary transition metal antimonides T5T ' Sb-1-x(2+x) (T = Ti, Zr, Hf; T ' = Fe, Co, Ni, Cu, Ru, Rh, Pd, Cd) with Nb5SiSn2 (ordered W5Si3, filled V4SiSb2) type structure

摘要

Fifteen new ternary antimonides T5T'Sb-1-x(2+x) were synthesized by reaction of the elemental components in an arc-melting furnace. They crystallize with a tetragonal structure first reported for Nb5SiSn2 (space group I4/mcm, Z = 4.) A structure refinement from four-circle X-ray diffractometer data of Hf5Fe1-xSb2+x (a = 1086.0(1) pm, c = 550.1(1) pm, R = 0.033 for 270 structure factors and 18 variable parameters) showed deviations from the ideal occupancy for two atomic sites, resulting in the composition Hf4.929(3)Fe0.67(1)Sb2.33(1). Structure refinements from X-ray powder data resulted in the formula Ti5Ni0.45(2)Sb2.55(2), while no deviation from the ideal composition was observed for Ti5RhSb2. The crystal structures of these compounds are discussed together with those of related binary and ternary compounds. [References: 25]