Campus Units

Ames Laboratory, Chemistry, Materials Science and Engineering

Document Type

Article

Publication Version

Published Version

Publication Date

2003

Journal or Book Title

Inorganic Chemistry

Volume

42

Issue

25

First Page

8223

Last Page

8229

DOI

10.1021/ic034941z

Abstract

One critical parameter influencing the structural nature of the phase transitions in magnetocaloric materials Gd5(SixGe1-x)4 is the Si/Ge ratio (x/1 − x), because transition temperatures and structures depend crucially on this value. In this study, single-crystal X-ray diffraction indicates that Si and Ge atoms are neither completely ordered nor randomly mixed among the three crystallographic sites for these elements in these structures. Ge atoms enrich the T sites linking the characteristic slabs in these structures, while Si atoms enrich the T sites within them. Decomposition of the total energy into site and bond energy terms provides a rationale for the observed distribution, which can be explained by symmetry and electronegativity arguments. For any composition in Gd5(SixGe1-x)4, a structure map is presented that will allow for a rapid assessment of the specific structure type.

Comments

Reprinted (adapted) with permission from Inorg. Chem., 2003, 42 (25), pp 8223–8229. Copyright 2003 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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