Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
Inorg Chem. 2013 Jun 17;52(12):7261-70. doi: 10.1021/ic400933v. Epub 2013 May 28.
Four series of ternary rare-earth zinc arsenides have been prepared by reaction of the elements at 750 °C: RE4Zn(2-x)As5 forming for RE = La-Nd, Sm; and RE5Zn(2-x)As6, RE6Zn(2-x)As7, RE7Zn(2-x)As8 forming for RE = Ce, Pr, Nd, Sm. They crystallize in trigonal structure types in space group P3m1 with Z = 1 for RE4Zn(2-x)As5 and RE7Zn(2-x)As8, or space group R3m1 with Z = 3 for RE5Zn(2-x)As6 and RE6Zn(2-x)As7. Through the structural principle of intergrowing rocksalt-type [REAs] slabs of variable thickness within a parent CaAl2Si2-type structure containing Zn-deficient [Zn(2-x)As2] slabs built from edge-sharing Zn-centered tetrahedra, these ternary arsenides belong to a homologous series with the formulation REZn(2-x)As2·n(REAs) (n = 3, 4, 5, 6). Quaternary derivatives Ce4(Mn,Zn)(2-x)As5 and Ce6(Mn,Zn)(2-x)As7 were also obtained in which Mn partially substitutes for Zn. Band structure calculations predict that the electronic properties can be gradually modified from semiconducting to semimetallic behavior as more [REAs] slabs are introduced.
已通过元素在 750°C 下的反应制备了四组三元稀土锌砷化物：RE4Zn(2-x)As5（RE = La-Nd、Sm）和 RE5Zn(2-x)As6、RE6Zn(2-x)As7、RE7Zn(2-x)As8（RE = Ce、Pr、Nd、Sm）。它们在空间群 P3m1 中结晶为三方晶系结构，Z = 1，对于 RE4Zn(2-x)As5 和 RE7Zn(2-x)As8，或在空间群 R3m1 中结晶为三方晶系结构，Z = 3，对于 RE5Zn(2-x)As6 和 RE6Zn(2-x)As7。通过互层岩盐型[REAs]片的结构原理，在包含 Zn 不足的[Zn(2-x)As2]片的母体 CaAl2Si2 型结构中，[REAs]片的厚度可变，这些三元砷化物属于同系列，通式为 REZn(2-x)As2·n(REAs)（n = 3、4、5、6）。还获得了四元衍生物 Ce4(Mn,Zn)(2-x)As5 和 Ce6(Mn,Zn)(2-x)As7，其中 Mn 部分取代了 Zn。能带结构计算预测，随着更多[REAs]片的引入，电子性质可以从半导体逐渐修改为类金属行为。
