Rare earth metal-rich indides RE14Rh3−xIn3 (RE=Y, Dy, Ho, Er, Tm, Lu)

The rare earth (RE) metal-rich indides RE14Rh3–xIn3 (RE=Y, Dy, Ho, Er, Tm, Lu) can be synthesized from the elements by arc-melting or induction melting in tantalum crucibles. They were investigated by X-ray diffraction on powders and single crystals: Lu14Co3In3 type, space group P42/nmc, Z=4, a=961.7(1), c=2335.5(5) pm, wR2=0.052, 2047 F2 values, 62 variables for Y14Rh3In3, a=956.8(1), c=2322.5(5) pm, wR2=0.068, 1730 F2 values, 63 variables for Dy14Rh2.89(1)In3, a=952.4(1), c=2309.2(5) pm, wR2=0.041, 1706 F2 values, 63 variables for Ho14Rh2.85(1)In3, a=948.6(1), c=2302.8(5) pm, wR2=0.053, 1977 F2 values, 63 variables for Er14Rh2.86(1)In3, a=943.8(1), c=2291.5(5) pm, wR2=0.065, 1936 F2 values, 63 variables for Tm14Rh2.89(1)In3, and a=937.8(1), c=2276.5(5) pm, wR2=0.050, 1637 F2 values, 63 variables for Lu14Rh2.74(1)In3. Except Yb14Rh3In3, the 8g Rh1 sites show small defects. Striking structural motifs are rhodium-centered trigonal prisms formed by the RE atoms with comparatively short Rh–RE distances (271–284 pm in Y14Rh3In3). These prisms are condensed via common corners and edges building two-dimensional polyhedral units. Both crystallographically independent indium sites show distorted icosahedral coordination. The icosahedra around In2 are interpenetrating, leading to In2–In2 pairs (309 pm in Y14Rh3In3).