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Fernández-Carrión AJ, Rakhmatullin A, Yang L, Pitcher MJ, Massiot D, Porcher F, Allix M, Kuang X. Sodium Site Exchange and Migration in a Polar Stuffed-Cristobalite Framework Structure. Inorg Chem 2021; 60:4322-4331. [PMID: 33719424 DOI: 10.1021/acs.inorgchem.1c00319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The study of ionic dynamics in solids is essential to understanding and developing modern energy technologies. Here we study the ionic dynamics of orthorhombic Na2MgSiO4, an interesting case of a polar stuffed-cristobalite-type structure that contains two inequivalent Na sites within the channels of the magnesium silicate tetrahedral framework. Its preparation by a solid-state reaction method favors the presence of ∼2% of Na vacancies, converting it into a pure Na ionic conductor with an optimized ionic conductivity of ∼10-5 S cm-1 at 200 °C. The macroscopic migration has been characterized through impedance spectroscopy and molecular dynamics simulation, which proves the pure Na ionic character of the compound through hopping between Na1 and Na2 sites, forming three-dimensional migration zigzag-shaped paths. High-resolution solid-state 23Na magic-angle-spinning (MAS) NMR spectroscopy is employed to characterize the local structure and microscopic dynamics of Na-ion transport in Na2MgSiO4. Remarkably, variable-temperature 23Na MAS NMR and two-dimensional exchange spectroscopy evidence for the first time a Na site exchange phenomenon at room temperature, which further triggers Na ionic conduction at elevated temperatures.
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Affiliation(s)
- Alberto J Fernández-Carrión
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | | | - Li Yang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China
| | | | | | - Florence Porcher
- Laboratoire Léon Brillouin, CEA Saclay, Gif Sur Yvette 91191, France
| | - Mathieu Allix
- CNRS, CEMHTI, UPR 3079, Université Orléans, Orléans F-45071, France
| | - Xiaojun Kuang
- MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, P. R. China.,College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, P. R. China
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Buzlukov A, Trokiner A, Kozhevnikov V, Verkhovskii S, Yakubovsky A, Leonidov I, Gerashenko A, Stepanov A, Baklanova I, Tankeyev A. Vacancy ordering and oxygen dynamics in oxide ion conducting La1−xSrxGa1−xMgxO3−x ceramics: 71Ga, 25Mg and 17O NMR. J SOLID STATE CHEM 2011. [DOI: 10.1016/j.jssc.2010.10.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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