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dc.contributor.authorAshbrook, Sharon Elizabeth
dc.contributor.authorMitchell, Martin
dc.contributor.authorSneddon, Scott
dc.contributor.authorMoran, Robert
dc.contributor.authorde los Reyes, Massey
dc.contributor.authorLumpkin, Gregory
dc.contributor.authorWhittle, Karl
dc.identifier.citationAshbrook , S E , Mitchell , M , Sneddon , S , Moran , R , de los Reyes , M , Lumpkin , G & Whittle , K 2015 , ' New insights into phase distribution, phase composition and disorder in Y 2 (Zr,Sn) 2 O 7 ceramics from NMR spectroscopy ' , Physical Chemistry Chemical Physics , vol. 17 , no. 14 , pp. 9049-9059 .
dc.identifier.otherPURE: 171436062
dc.identifier.otherPURE UUID: 0f2b6358-d475-49e2-9cd8-b7f09e859d9b
dc.identifier.otherScopus: 84961316842
dc.identifier.otherORCID: /0000-0002-4538-6782/work/56638983
dc.identifier.otherWOS: 000351933600058
dc.descriptionThe authors would like to thank EPSRC for DTA awards to MM and SS, and for experimental and computational support (EP/E041825/1, EP/J501542/1 and EP/F018096/1). We thank EaStCHEM for computational support through the EaStCHEM Research Computing Facility.en
dc.description.abstractA combination of 89Y and 119Sn NMR spectroscopy and DFT calculations are used to investigate phase evolution, local structure and disorder in Y2Zr2−xSnxO7 ceramics, where a phase change is predicted, from pyrochlore to defect fluorite, with increasing Zr content. The ability of NMR to effectively probe materials that exhibit positional and compositional disorder provides insight into the atomic-scale structure in both ordered and disordered phases and, by exploiting the quantitative nature of the technique, we are able to determine detailed information on the composition of the phase(s) present and the average coordination number (and next-nearest neighbour environment) of the cations. In contrast to previous studies, a more complex picture of the phase variation with composition emerges, with single-phase pyrochlore found only for the Sn end member, and a single defect fluorite phase only for x = 0 to 0.6. A broad two-phase region is observed, from x = 1.8 to 0.8, but the two phases present have very different composition, with a maximum of 13% Zr incorporated into the pyrochlore phase, whereas the composition of the defect fluorite phase varies throughout. Preferential ordering of the anion vacancies in the defect fluorite phase is observed, with Sn only ever found in a six-coordinate environment, while remaining vacancies are shown to be more likely to be associated with Zr than Y. Our findings are then discussed in the light of those from previous studies, many of which utilize diffraction-based approaches, where, in most cases, a single phase of fixed composition has been assumed for the refinement procedure. The significant and surprising differences encountered demonstrate the need for complementary approaches to be considered for a detailed and accurate picture of both the long- and short-range structure of a solid to be achieved.
dc.relation.ispartofPhysical Chemistry Chemical Physicsen
dc.rightsCopyright 2015 the Authors. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (
dc.subjectQD Chemistryen
dc.titleNew insights into phase distribution, phase composition and disorder in Y2(Zr,Sn)2O7 ceramics from NMR spectroscopyen
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews.EaSTCHEMen
dc.contributor.institutionUniversity of St Andrews.School of Chemistryen
dc.description.statusPeer revieweden

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