Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

7-3-2017

Journal or Book Title

Journal of Materials Chemistry C

Volume

5

Issue

29

First Page

7215

Last Page

7221

DOI

10.1039/C7TC01967J

Abstract

The new complex intermetallic alloy, Cr22Zn72Sn24, with a giant cubic unit cell (space group Fmc, Z = 8, Pearson symbol cF944 with a = 25.083(3) Å) is reported. The structure can be described as a CsCl-type packing of two “Russian Doll” type intermetallic clusters: a 99-atom cluster, Cr@(Cr8Zn6)(Sn)24(Zn)60, composed of a central Cr atom encapsulated by three shells: a distorted rhombic dodecahedron, a snub-cube, and a rhombi-icosidodecahedron; and a 55-atom cluster, Cr@(Zn)12(Zn)30(Zn)12, also composed of a central Cr atom, but now surrounded by three different shells: an icosahedron, an icosidodecahedron, and a larger icosahedron. The two distinct clusters can be considered as “superatoms” that form the resulting nanometer-scale CsCl-type structure. Evaluating the electronic structure of this complex alloy structure yielded an alternative description, involving a 3-d network of vertex-connected, Cr-centered icosahedra and fragments of bcc metals. This description closely parallels the effective chemical bonding interactions, allowing for an understanding of the stability of this CMA. Magnetic and Seebeck coefficient measurements on self-flux grown crystals of Cr22Zn72Sn24 show it to be paramagnetic and metallic, in agreement with the results of electronic structure calculations.

Comments

This is a manuscript of an article published as Xie, Weiwei, Robert J. Cava, and Gordon J. Miller. "Packing of Russian doll clusters to form a nanometer-scale CsCl-type compound in a Cr–Zn–Sn complex metallic alloy." Journal of Materials Chemistry C 5, no. 29 (2017): 7215-7221. doi: 10.1039/C7TC01967J. Posted with permission.

Copyright Owner

The Royal Society of Chemistry

Language

en

File Format

application/pdf

Published Version

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