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arXiv · 1111.5230

RbFe2+Fe3+F6: Synthesis, Structure, and Characterization of a New Charge-Ordered Magnetically Frustrated Pyrochlore-Related Mixed-Metal Fluoride

Sun Woo Kim·Sang-Hwan Kim·P. Shiv Halasyamani·Mark A. Green·Kanwal Preet Bhatti·C. Leighton·Hena Das·Craig J. Fennie
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Abstract

A new charge-ordered magnetically frustrated mixed-metal fluoride with a pyrochlore-related structure has been synthesized and characterized. The material, RbFe2F6 (RbFe2+Fe3+F6) was synthesized through mild hydrothermal conditions. The material exhibits a three-dimensional pyrochlore-related structure consisting of corner-shared Fe2+F6 and Fe3+F6 octahedra. In addition to single crystal diffraction data, neutron powder diffraction and magnetometry measurements were carried out. Magnetic data clearly reveal strong antiferromagnetic interactions (a Curie-Weiss temperature of -270 K) but sufficient frustration to prevent ordering until 16 K. No structural phase transformation is detected from the variable temperature neutron diffraction data. Infrared, UV -vis, thermogravimetric, and differential thermal analysis measurements were also performed. First-principles density functional theory (DFT) electronic structure calculations were also done. Crystal data: RbFe2F6, orthorhombic, space group Pnma (No. 62), a = 7.0177(6) {\AA}, b = 7.4499(6) {\AA}, c = 10.1765(8) {\AA}, V = 532.04(8) {\AA}3, Z = 4.

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Sun Woo Kim, Sang-Hwan Kim, P. Shiv Halasyamani, Mark A. Green, Kanwal Preet Bhatti, C. Leighton, Hena Das, Craig J. Fennie. 2011-11-22. RbFe2+Fe3+F6: Synthesis, Structure, and Characterization of a New Charge-Ordered Magnetically Frustrated Pyrochlore-Related Mixed-Metal Fluoride. https://doi.org/10.1039/c2sc00765g

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