He Hua, Stoyko Stanislav S, Mar Arthur, Bobev Svilen
Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
Acta Crystallogr C. 2013 May;69(Pt 5):455-9. doi: 10.1107/S010827011300766X. Epub 2013 Apr 9.
Dirubidium pentacadmium tetraarsenide, Rb2Cd5As4, dirubidium pentazinc tetraantimonide, Rb2Zn5Sb4, and the solid-solution phase dirubidium pentacadmium tetra(arsenide/antimonide), Rb2Cd5(As,Sb)4 [or Rb2Cd5As3.00(1)Sb1.00(1)], have been prepared by direct reaction of the component elements at high temperature. These compounds are charge-balanced Zintl phases and adopt the orthorhombic K2Zn5As4-type structure (Pearson symbol oC44), featuring a three-dimensional M5Pn4 framework [M = Zn or Cd; Pn is a pnicogen or Group 15 (Group V) element] built of linked MPn4 tetrahedra, and large channels extending along the b axis which host Rb(+) cations. The As and Sb atoms in Rb2Cd5(As,Sb)4 are randomly disordered over the two available pnicogen sites. Band-structure calculations predict that Rb2Cd5As4 is a small-band-gap semiconductor and Rb2Zn5Sb4 is a semimetal.
五镉四砷化二铷（Rb₂Cd₅As₄）、五锌四锑化二铷（Rb₂Zn₅Sb₄）以及固溶体相五镉四（砷化物/锑化物）化二铷（Rb₂Cd₅(As,Sb)₄ [或Rb₂Cd₅As₃.₀₀(1)Sb₁.₀₀(1)]）是通过在高温下使各组成元素直接反应制备而成的。这些化合物是电荷平衡的津特耳相，采用正交晶系的K₂Zn₅As₄型结构（皮尔逊符号oC44），其特征是具有一个三维的M₅Pn₄骨架[M = Zn或Cd；Pn为氮族元素或第15族（Ⅴ族）元素]，该骨架由相连的MPn₄四面体构成，并且有沿b轴延伸的大通道，其中容纳Rb(+)阳离子。在Rb₂Cd₅(As,Sb)₄中，As和Sb原子在两个可用的氮族元素位点上随机无序分布。能带结构计算预测，Rb₂Cd₅As₄是一种小带隙半导体，而Rb₂Zn₅Sb₄是一种半金属。
