Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

2004

Journal or Book Title

Inorganic Chemistry

Volume

43

Issue

6

First Page

1912

Last Page

1919

DOI

10.1021/ic030265p

Abstract

The newly reported icosahedral quasicrystalline phase ∼Sc3Cu2.1Zn12.9 was approached through four synthetic, structural, and EDX analyses of the range of approximants formed by systematic substitutions of 0−4 Zn by Cu in the reported Sc3Zn17 as well as for the corrected Sc3Zn18(ScZn6) composition. Structures of high yield products of the 0, 1, 2, 3 Cu atom steps all refined as isotypic Sc3CuyZn18-y phases (Im3̄, Z = 8, a = 13.8311(5) to 13.7528(5) Å for 0 ≤ y ≤2.2), basically isostructural with RCd6 phases known for many rare-earth elements. The present phases all exhibit the novel feature of disordered zinc tetrahedra in the center of four concentric polyhedral clusters:  pentagonal dodecahedron (Zn/Cu), icosahedron (Sc), icosidodecahedron (Zn), and triacontahedron (Zn). The Cu tuning process reduces both the average electron count per atom (e/a) to 2.04 and the average atom size until major amounts of the zinc-poorer quasicrystal separate along with the present normal crystalline phase near four added Cu. The Cu is an important neighbor to the disordered Zn atoms. The approximant structure repeatedly exhibits components with pseudo-icosahedral symmetry.

Comments

This is an article from Inorganic Chemistry 43 (2004): 1912, doi: 10.1021/ic030265p. Posted with permission.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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