Rare earth-rich cadmium compounds RE4TCd(T=Co,Ru,and Rh)with Gd4RhIn type structure

摘要

The rare earth-rich cadmium compounds RE4TCd(RE=Y,La-Nd,Sm,and Gd-Tm,Lu;T=Co,Ru,and Rh)were prepared from the elements in sealed tantalum ampoules in an induction furnace.All samples were characterized by X-ray powder diffraction.The structures of Y4RuCd(a=1362.5(1)pm),La4RuCd(a=1415.9(1)pm),Gd4RuCd(a=1368.8(2)pm),La4CoCd(a=1417.9(4)pm),Gd4CoCd(a=1356.1(1)pm),and Gd4RhCd(a=1368.7(1)pm)were refined from single crystal X-ray diffractometer data.The RE4TCd compounds crystallize with the cubic Gd4RhIn type structure,space group F43m.The transition metal atoms have tricapped trigonal prismatic rare earth coordination.The trigonal prisms are condensed via common edges,forming a rigid three-dimensional network with adamantane symmetry.Voids in these networks are filled by Cd4 tetrahedra(304 pm Cd-Cd in Gd4CoCd)and polyhedra of the RE1 atoms.The crystal chemical peculiarities are briefly discussed.