文摘
The intermetallic compounds YbAu2In4 and Yb2Au3In5 were obtained as single crystals in high yield from reactions run in liquid indium. Single crystal X-ray diffraction data of YbAu2In4 showed that it crystallizes as a new structure type in the monoclinic space group P21/m and lattice constants a = 7.6536(19) Å, b = 4.5424(11) Å, c = 9.591(2) Å and β = 107.838(4)°. The YbAu2In4 compound is composed of a complex [Au2In4]3− polyanionic network in which the rare-earth ions are embedded. Yb2Au3In5 crystallizes in the polar space group Cmc21 with the Y2Rh3Sn5 type structure and lattice constants a = 4.5351(9) Å, b = 26.824(5) Å, and c = 7.4641(15) Å. The gold and indium atoms define a complex three-dimensional [Au3In5] network with a broad range of Au−In (2.751(2) Å−3.0518(16) Å) and In−In (3.062(3) Å−3.3024(19) Å) distances. Magnetic susceptibility measurements of YbAu2In4 revealed a transition at 25 K. Below the transition, the susceptibility of YbAu2In4 follows Curie−Weiss behavior with an effective paramagnetic moment of 0.79 μB/Yb. Magnetic susceptibility measurements on Yb2Au3In5 show a mixed valent ytterbium and the magnetic moment within the linear region (<100 K) of 1.95 μB/Yb. Heat capacity data for YbAu2In4 and Yb2Au3In5 give Debye temperatures of 185 and 153 K, respectively.