55127-03-2Relevant academic research and scientific papers
Structure of the equiatomic liquid alloys K-Sb, K-Bi, and Rb-Bi over a wide temperature range
Hochgesand,Winter
, p. 7551 - 7556 (2000)
We report on neutron diffraction measurements on the equiatomic liquid alloys K-Sb, K-Bi, and Rb-Bi up to temperatures of T = 1800K. The prepeaks in the resulting total structure factors S(Q) are indicative of intermediate range ordering. The shift of the prepeak positions towards smaller momentum transfer Q with increasing temperature suggests increasing distances between the structural polyanionic units. From reverse Monte Carlo (RMC) simulations the prepeak is assigned essentially to correlations between the polyvalent metal atoms (Sb or Bi), remaining even up to the highest temperatures measured. The simulations lead to models exhibiting Sb (or Bi) atoms clustered in short chains and dumbbells rather than in higher coordinated clusters or networklike structures.
Alkali Metal Bismuthides ABi and ABi2 - Synthesis, Crystal Structure, Properties
Emmerling, Franziska,Laengin, Nina,Petri, Denis,Kroeker, Martin,Roehr, Caroline
, p. 171 - 178 (2008/10/09)
The Zintl phases ABi (A = K/Rb/Cs; monoclinic, space group, P2 1/c, a = 1422.3(2)/1474.2(2)/1523.7(3), b = 724.8(1)/ 750.2(1)7773.7(1), c = 1342.0(2)/1392.1(2)/1439.9(2)pm and β = 113.030(3)/113.033(2)/112.722(3)°, Z = 16) crystallize with the β-CsSb structure type containing chains of two-connected Bi atoms. Hence, and according to calculated electronic structures, they are semiconductors with small band gaps of approx. 0.5 eV. In contrast, the compounds ABi2 (A = K/Rb/Cs; cubic, space group Fd3m, a = 952.1(2)/962.4(8)/972.0(3) pm, Z = 8) belong to the Laves phases, showing a typical metallic electrical conductivity and no band gaps.
Bismuth polyanions in solution: Synthesis and structural characterization of (2,2,2-crypt-A)2Bi4 (A = K, Rb) and the formation of the laves phases ABi2 (A = K, Rb, Cs) from solution
Kuznetsov, Alexei N.,Faessler, Thomas F.
, p. 2537 - 2541 (2008/10/08)
The possibility to synthesize and isolate different types of bismuth polyanions by dissolving various intermetallic precursors (binary samples from A-Bi or ternary samples from A-A'-Bi systems, A and A' = K, Rb, Cs) in ethylenediamine or dimethylformamide in the presence of sequestering agents (2,2,2-crypt or 18-crown-6) was investigated. The crystals of (2,2,2-crypt-K)2Bi4 (1) and (2,2,2-crypt-Rb)2Bi4 (2) compound were obtained from such solutions, the latter for the first time, and their structures were determined. The two compounds are isostructural (P1, Z = 1, a = 11.052(2) A, b = 11.370(2) A, c = 11.698(2) A, α = 61.85(3)°, β = 82.58(3)°, γ = 81.87(3)°, R1 = 0.058, wR2 = 0.149 for 1 and a = 11.181(2) A, b = 11.603(2) A, c = 11.740(2) A, α = 61.96(3)°, β = 81.45(3)°, γ = 82.26(3)°, R1 = 0.041, wR2 = 0.109) and contain Bi42- square planar cluster anions and cryptated alkali metal cations. In the case of the presence of 18-crown-6 the Laves phases ABi2 (A = K, Rb, Cs) could be isolated from the solutions. A mechanism for the formation of ABi2 is proposed.
