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Potassium Disorder in the Defect Pyrochlore KSbTeO6: A Neutron Diffraction Study
13 January 2017

José Antonio Alonso,* Sergio Mayer, Horacio Falcón, Xabier Turrillas and María Teresa Fernández-Díaz. Crystals20177(1), 24

DOI: https://doi.org/10.3390/cryst7010024

KSbTeO6 defect pyrochlore has been prepared from K2C2O4, Sb2O3, and 15% excess TeO2 by solid-state reaction at 850 °C. Direct methods implemented in the software EXPO2013 allowed establishing the basic structural framework. This was followed by a combined Rietveld refinement from X-ray powder diffraction (XRD) and neutron powder diffraction (NPD) data, which unveiled additional structural features. KSbTeO6 is cubic, a = 10.1226(7) Å, space group http://www.w3.org/1998/Math/MathML" display="inline">Fd3¯m" role="presentation" style="box-sizing: border-box; max-height: none; display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 13px; text-indent: 0px; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Fd3¯m , Z = 8 and it is made of a mainly covalent framework of corner-sharing (Sb,Te)O6 octahedra, with weakly bonded K+ ions located within large cages. The large K-O distances, 3.05(3)–3.07(3) Å, and quite large anisotropic atomic displacement parameters account for the easiness of K+exchange for other cations of technological importance

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Oxides for new-generation electronics

Potassium Disorder in the Defect Pyrochlore KSbTeO6: A Neutron Diffraction Study



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