An Exhaustive Symmetry Approach to Structure Determination: Phase Transitions in Bi2Sn2O7

Lewis, James W.; Payne, Julia L.; Evans, Ivana Radosavljevic; Stokes, Harold T.; Campbell, Branton J.; Evans, John S.O.

doi:10.1021/jacs.6b04947

An Exhaustive Symmetry Approach to Structure Determination: Phase Transitions in Bi2Sn2O7

Lewis, James W.; Payne, Julia L.; Evans, Ivana Radosavljevic; Stokes, Harold T.; Campbell, Branton J.; Evans, John S.O.

Authors

James W. Lewis

Julia L. Payne

Ivana Radosavljevic Evans

Harold T. Stokes

Branton J. Campbell

Professor John Evans john.evans@durham.ac.uk
Professor

Contributors

Professor Ivana Evans ivana.radosavljevic@durham.ac.uk
Other

Abstract

The exploitable properties of many materials are intimately linked to symmetry-lowering structural phase transitions. We present an automated and exhaustive symmetry-mode method for systematically exploring and solving such structures which will be widely applicable to a range of functional materials. We exemplify the method with an investigation of the Bi2Sn2O7 pyrochlore, which has been shown to undergo transitions from a parent γ cubic phase to β and α structures on cooling. The results include the first reliable structural model for β-Bi2Sn2O7 (orthorhombic Aba2, a = 7.571833(8), b = 21.41262(2), and c = 15.132459(14) Å) and a much simpler description of α-Bi2Sn2O7 (monoclinic Cc, a = 13.15493(6), b = 7.54118(4), and c = 15.07672(7) Å, β = 125.0120(3)°) than has been presented previously. We use the symmetry-mode basis to describe the phase transition in terms of coupled rotations of the Bi2O′ anti-cristobalite framework, which allow Bi atoms to adopt low-symmetry coordination environments favored by lone-pair cations.

Citation

Lewis, J. W., Payne, J. L., Evans, I. R., Stokes, H. T., Campbell, B. J., & Evans, J. S. (2016). An Exhaustive Symmetry Approach to Structure Determination: Phase Transitions in Bi2Sn2O7. Journal of the American Chemical Society, 138(25), 8031-8042. https://doi.org/10.1021/jacs.6b04947

Journal Article Type	Article
Acceptance Date	May 13, 2016
Online Publication Date	Jun 1, 2016
Publication Date	Jun 29, 2016
Deposit Date	Aug 5, 2016
Publicly Available Date	Aug 5, 2016
Journal	Journal of the American Chemical Society
Print ISSN	0002-7863
Electronic ISSN	1520-5126
Publisher	American Chemical Society
Peer Reviewed	Peer Reviewed
Volume	138
Issue	25
Pages	8031-8042
DOI	https://doi.org/10.1021/jacs.6b04947

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