Campus Units

Ames Laboratory, Chemistry, Physics and Astronomy

Document Type

Article

Publication Version

Published Version

Publication Date

2010

Journal or Book Title

Inorganic Chemistry

Volume

49

Issue

24

First Page

11505

Last Page

11515

DOI

10.1021/ic101671k

Abstract

A series of rhombohedrally distorted γ-brass structures containing a mixture of magnetically active 3d elements, Cr and Fe, Cr1−xFexGa, is investigated crystallographically. These structures consist of chains of trans-face-sharing Ga-centered transition metal icosahedra. Neutron powder diffraction specifically on Cr0.5Fe0.5Ga, which could be prepared as a single phase material, gave lattice constants (11 K) a = 12.5172(2) Å and c = 7.8325(2) Å and a refined composition of Cr0.502(6)Fe0.498Ga = Cr6.523Fe6.477Ga13 and revealed partial ordering of Cr and Fe atoms among three crystallographic sites. Magnetic susceptibility and magnetization studies of Cr0.5Fe0.5Ga showed the onset of magnetic ordering at ca. 25 K. Theoretical calculations suggested both site-energy and bond-energy factors influencing the Cr/Fe distribution. Heteroatomic interactions significantly affect exchange interactions and create low local magnetic moments. Models created to mimic Cr0.5Fe0.5Ga showed ferromagnetic Fe−Fe and antiferromagnetic Cr−Fe interactions, with an overall ferrimagnetic ordering.

Comments

Reprinted (adapted) with permission from Inorg. Chem., 2010, 49 (24), pp 11505–11515. Copyright 2010 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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