Indides RE3T2In4 (RE = Y, Gd–Tm, Lu; T = Ni, Ru, Rh) with a ZrNiAl superstructure
AbstractThree series of rare earth-transition metal-indides RE3T2In4 (RE=Y, Gd–Tm, Lu; T=Ni, Ru, Rh) were synthesized from arc-melted RE3T2 precursor compounds and indium tear shot in sealed niobium ampoules using different annealing sequences. The new indides crystallize with the hexagonal Lu3Co2In4-type structure, space group P6̅. All samples were characterized on the basis of Guinier powder patterns and six structures were refined from single crystal X-ray diffractometer data. The RE3T2In4 structures are derived from the ZrNiAl type through RE/In ordering, paralleled by a symmetry reduction from P6̅2m to P6̅. This induces twinning for some of the investigated crystals. The main crystal chemical motifs of the RE3T2In4 structures are trigonal prisms of rare earth, respectively indium atoms that are filled by the transition metals.