The crystal structure of alpha-La2Mo2O9 and the structural origin of the oxide ion migration pathway

Evans, I.R.; Howard, J.A.K.; Evans, J.S.O.

Abstract

We describe for the first time the full 3D atomic structure of room-temperature alpha-La2Mo2O9. The material, despite its simple chemical formula, has a remarkable 312 crystallographically unique atoms and is thus one of the most complex oxide structures reported to date. Despite this complexity, the structural results offer significant insight into the O2- migration pathway in the anion conducting high-temperature form, beta-La2Mo2O9. The material contains a mixture of 4, 5, and 6 coordinated Mo sites, suggesting that variable Mo coordination number is a key factor in providing a low-energy O2- conduction pathway. We provide quantitative analysis showing that the positions in the ordered array of 216 oxygen sites of alpha-La2Mo2O9 are directly related to the average sites occupied in beta-La2Mo2O9, providing compelling evidence that the high-temperature conducting form of the material has a time-averaged version of the low-temperature structure.

Citation

Evans, I., Howard, J., & Evans, J. (2005). The crystal structure of alpha-La2Mo2O9 and the structural origin of the oxide ion migration pathway. Chemistry of Materials, 17(16), 4074-4077. https://doi.org/10.1021/cm050049%2B

• Journal Article Type: Article
• Publication Date: Aug 1, 2005
• Deposit Date: May 10, 2007
• Journal: Chemistry of Materials
• Print ISSN: 0897-4756
• Electronic ISSN: 1520-5002
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 17
• Issue: 16
• Pages: 4074-4077
• DOI: https://doi.org/10.1021/cm050049%2B
• Public URL: https://durham-repository.worktribe.com/output/1602701