Lanthanoids. I 2800. Ln2+xI2M2+y (Ln: Ce, Gd, Y; M: Al, Ga): Reduced Rare Earth Halides with a. Hexagonal Metal Atom Network. â The title compounds are ...
2007
Lanthanoids I 2800
30- 018
Ln2+xI2M2+y (Ln: Ce, Gd, Y; M: Al, Ga): Reduced Rare Earth Halides with a Hexagonal Metal Atom Network. — The title compounds are prepared from mixtures of Ln (Ln: Ce, Gd, Y), LnI3, and Al or Ga at 930—950 °C (argon, 10—15 d, >90% yield). The samples are characterized by powder XRD, extended Hueckel and DFT calculations, and electrical and magnetic measurements. The non-stoichiometric Ce2+xI2Al 2+y and Ce2+x I2Ga2+y compounds crystallize in the rhombohedral space group R3m with Z = 3. The stoichiometric Gd2I2Ga2 and Y2I2Ga2 compounds crystallize in the trigonal space group P3m1 with Z = 1. Their structures feature M-centered (M: Al, Ga) Ln trigonal prisms condensed via common rectangular faces. Gd2I2Ga 2 exhibits a metal-insulator transition at 40 K. — (LUKACHUK, M.; ZHENG*, C.; MATTAUSCH, H.; BANKS, M. G.; KREMER, R. K.; SIMON, A.; Z. Naturforsch., B: Chem. Sci. 62 (2007) 5, 633-641; Dep. Chem. Biochem., North. Ill. Univ., DeKalb, IL 60115, USA; Eng.) — W. Pewestorf
