Sc 11− xYb xGe 10 ( x≈5): a substitution variant with Ho 11Ge 10 type structure showing partial order on the rare earth sites

Abstract

Sc 11− x Yb x Ge 10 ( x≈5) is a new ternary germanide which is in equilibrium with binary Sc 11Ge 10 at 600°C. Both phases crystallize with the tetragonal Ho 11Ge 10 structure type. The ternary phase (space group I4/ mmm, a=1.0505(7), c = 1.587(2) nm) was investigated by single crystal X-ray diffraction, and found to contain four rare earth sites of which one (CN = 15) is fully occupied by Sc, and the other three (CN = 15, 17, 17) by a one-to-two mixture of Sc and Yb. The partial ordering on the rare earth sites is the first such observed for this structure type.