Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

2010

Journal or Book Title

Chemistry of Materials

Volume

22

Issue

5

First Page

1798

Last Page

1806

DOI

10.1021/cm903300y

Abstract

EuAgxAl11−x phases adopting the BaHg11-type structure (space group Pmm, Z = 3) were synthesized with high yield by arc melting a mixture loaded as “EuAg3.5Al7.5” and annealing at 500 °C for 40 days. This phase has a very narrow phase width around EuAg4.0Al7.0; and it is unstable at 600 and 700 °C, at which it transforms into other phases. Magnetometry indicates that Eu is divalent, which gives the valence electron concentration per Ag/Al atom as 2.45 e/atom, higher than in the BaCd11-type phases in the Eu−Ag−Al system (2.10−2.30 e/atom). First principles electronic structure calculations, using a computational model structure built by simulating the crystallographic results as well as maximizing the number of heteroatomic (Ag−Al) contacts, can explain why the cubic BaHg11-type structure is favored at higher valence electron concentration than the tetragonal BaCd11-type structure.

Comments

Reprinted (adapted) with permission from Chem. Mater., 2010, 22 (5), pp 1798–1806. Copyright 2010 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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