Campus Units

Chemistry, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

2010

Journal or Book Title

Inorganic Chemistry

Volume

49

Issue

22

First Page

10436

Last Page

10444

DOI

10.1021/ic101356n

Abstract

The realm of Tsai-type (YCd6-type) quasicrystals (QCs) and their approximants (ACs) continues to expand to the east in the periodic table. The heavy tetrel Sn is now one of the major components in the new Ca15.0(5)Au60.0(4)Sn25.0(2) (atom %) icosahedral QC and in the corresponding 1/1 and 2/1 ACs. (The 2/1 AC with Yb is also established.) Single-crystal X-ray diffraction on a 1/1 AC gives the refined formula of Ca3Au14.36(3)Sn4.38(5) in space group Im3̅, a = 15.131(1) Å, whereas a representative 2/1 AC gives Ca13Au47.2(1)Sn28.1(1), Pa3̅ and a = 24.444(1) Å. Both ACs contain five-shell multiply endohedral triacontahedral clusters as the common building blocks, as in the parent structure of YCd6. The 2/1 AC also contains four Ca2-dimer-centered prolate rhombohedra (PRs) in the unit cell. The long-range order between triacontahedra and PRs in the 2/1 AC is the same as those in Bergman-type 2/1 ACs. A TB-LMTO-ASA calculation on an ideal 1/1 AC model reveals a shallow pseudogap in the total densities-of-states data around the Fermi energy, as expected. The depth of the pseudogap is considerably enhanced through interactions between the Ca 3d states and s and p states of Au and Sn.

Comments

This is an article from Inorganic Chemistry 49 (2010): 10436, doi: 10.1021/ic101356n. Posted with permission.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Share

COinS