Crystal structure of the intermetallic compound lithium aluminum germanium, Li16Al4Ge7

Abstract

AUGe7Lii6, tetragonal, I4\/amd (No. 141), a = 6.193(2) Â, c = 12.267(3) A, V= 470.5 Â, Z = 1, Rgt(F) = 0.034, wRTef(F) = 0.040, T = 293 K. Source of material The compound Lii6AUGe7 was prepared from Li and Al bulk metals and Ge powder (atomic proportion 15:3:6) inserted in a Ta reactor weld-sealed under argon and protected in a stainless container. The product was obtained by reacting the elements for 11 h at 873K, homogenizing for 5 h at 1173K, and single crystals were formed by cooling the melt at the rate of 25 K/h to ambient temperature. The air-sensitive crystals were selected in a glove box, inserted into Lindemann capillaries. Cell parameters and space group were initially determined by oscillation and Weissenberg techniques. The Al:Ge ratio of nearly 0.6:1 has been confirmed from elemental analysis (SEM) of single crystals. The best diffracting crystal was used for data collection. Table 1. Data collection and handling. Crystal: dark grey platelet, size 0.02 χ 0.06 χ 0.09 mm Wavelength: Mo Ka radiation (0.71069 A) μ· 111.86 cm 1 Diffractometer, scan mode: Nonius CAD4, ω/20 73.98° N(hkl)m 2 σ(lobs), 131 N(param)Krmoi· 15 Programs: SHELXS-97 [4], SHELXL-76 [5], DIAMOND [6], CRYSTALS [7] Table 2. Atomic coordinates and displacement parameters (in A). Atom Site Occ. * y ζ Uiso Li(3) 8e 0.38(6) 0 1/4 0.118(4) 0.013(8) * Correspondence author (e-mail: mtillard@univ-montp2.fr) Unauthenticated Download Date | 2/16/16 5:16 AM