Mondal Amit, Pan Rahul, Kuila Sandip Kumar, Dey Riju, Jana Partha Pratim
Department of Chemistry, IIT Kharagpur, Kharagpur 721 302, India.
Acta Crystallogr B Struct Sci Cryst Eng Mater. 2024 Dec 1. doi: 10.1107/S2052520624008096.
A detailed structural analysis of the Zn-rich δ-MnZn phase using single-crystal X-ray diffraction is presented. The δ phase has been synthesized by the high-temperature synthetic route. The structure crystallizes in space group P6/mmc (Pearson symbol hP556) with unit-cell parameters: a = b = 12.9051 (2) Å and c = 57.640 (1) Å. The 556 atoms are distributed over 52 Wyckoff positions in the hexagonal unit cell: seven ordered Mn sites, 37 ordered Zn sites and eight positionally disordered Zn sites. The structure predominantly consists of Frank-Kasper polyhedra (endohedral icosahedra Zn and icosioctahedron Zn) and four distinct types of glue Zn atoms. The structure comprises a 127-atom supercluster (MnZn), a 38-atom extended Pearce cluster (MnZn), a 46-atom L-tetrahedron (MnZn), a Friauf polyhedron (Zn), a disordered icosahedral cluster (MnZn) and four glue Zn atoms. Positionally disordered Zn sites around an Mn site can be visualized as the superimposition of three differently oriented Zn icosahedra.
本文利用单晶X射线衍射对富锌δ-MnZn相进行了详细的结构分析。δ相是通过高温合成路线制备的。该结构属于空间群P6/mmc（皮尔逊符号hP556），晶胞参数为：a = b = 12.9051 (2) Å，c = 57.640 (1) Å。556个原子分布在六方晶胞的52个魏科夫位置上：7个有序的Mn位点、37个有序的Zn位点和8个位置无序的Zn位点。该结构主要由弗兰克-卡斯帕多面体（内面二十面体Zn和二十面体八面体Zn）和四种不同类型的胶合Zn原子组成。该结构包含一个127原子的超簇（MnZn）、一个38原子的扩展皮尔斯簇（MnZn）、一个46原子的L-四面体（MnZn）、一个弗里奥夫多面体（Zn）、一个无序二十面体簇（MnZn）和四个胶合Zn原子。Mn位点周围位置无序的Zn位点可以看作是三个不同取向的Zn二十面体的叠加。
