Department of Chemistry , IIT Kharagpur , Kharagpur - 721302 , India.
Department of Physics , IIT Kharagpur , Kharagpur - 721302 , India.
Inorg Chem. 2018 Oct 1;57(19):11970-11977. doi: 10.1021/acs.inorgchem.8b01518. Epub 2018 Sep 12.
A new ternary compound CuZnSb was synthesized by high temperature solid state synthesis and characterized by single crystal X-ray diffraction and energy dispersive X-ray analysis. The ternary CuZnSb crystallizes in the tetragonal crystal system with the space group P4/ nmm (129), and its unit cell contains 10 atoms which are distributed over 4 independent crystallographic positions. The structure is built up with [CuSb] slabs that correspond to the unit cells of CuSb and planar 4 nets of Zn atoms. The planar nets of Zn atoms are interspersed between two adjacent [CuSb] slabs. The structure can be viewed as alternating units of CuSb and CsCl type β'-brass (CuZn) structures in the [001]. An unusual atomic ordering of two neighboring transition metals Cu and Zn is observed and is confirmed by first principle calculations. The atomic ordering of Cu and Zn is retained from binary β'-brass structure (CuZn) to ternary CuZnSb. Total energy calculations confirmed the experimental model of Cu/Zn ordering to be the most stable in the structure of CuZnSb. The calculated density of states (DOS) and crystal orbital Hamiltonian population (COHP) explain the stability and bonding characteristics in the structure of CuZnSb. The implication of the persistent Cu/Zn ordering in ternary phases for materials design is emphasized.
通过高温固相合成合成了一种新的三元化合物 CuZnSb，并通过单晶 X 射线衍射和能量色散 X 射线分析进行了表征。三元 CuZnSb 结晶在四方晶系中，空间群为 P4/ nmm(129)，其晶胞包含 10 个原子，分布在 4 个独立的晶体学位置上。结构由 [CuSb] 片层构成，对应于 CuSb 的晶胞和 Zn 原子的平面 4 网。Zn 原子的平面网散布在两个相邻的 [CuSb] 片层之间。该结构可以看作是在 [001] 方向上交替的 CuSb 和 CsCl 型 β'-黄铜 (CuZn) 结构单元。观察到相邻两个过渡金属 Cu 和 Zn 的原子有序排列，并通过第一性原理计算得到证实。从二元 β'-黄铜结构 (CuZn) 到三元 CuZnSb，Cu 和 Zn 的原子有序排列得以保留。总能量计算证实了实验模型中 Cu/Zn 有序排列是 CuZnSb 结构中最稳定的。计算的态密度 (DOS) 和晶体轨道哈密顿人口 (COHP) 解释了 CuZnSb 结构中的稳定性和键合特性。强调了三元相中持续的 Cu/Zn 有序排列对材料设计的意义。
