Ion mobility, phase transitions and conductivity in the fluorides (NH4)6LiZr3HfF23 and (NH4)6LiZrHf3F23
| Autor: | N. N. Savchenko, V. Ya. Kavun, M. M. Polyantsev, A. B. Podgorbunskii, T. F. Antokhina |
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| Rok vydání: | 2019 |
| Předmět: |
Phase transition
Materials science Analytical chemistry Ionic bonding Activation energy Conductivity Atmospheric temperature range Condensed Matter Physics Electronic Optical and Magnetic Materials Ion Inorganic Chemistry chemistry.chemical_compound chemistry Materials Chemistry Ceramics and Composites Fast ion conductor Physical and Theoretical Chemistry Fluoride |
| Zdroj: | Journal of Solid State Chemistry. 270:524-530 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2018.12.024 |
| Popis: | Ion mobility, phase transitions, thermal and electrophysical properties in (NH4)6LiZr3HfF23 and (NH4)6LiZrHf3F23 fluorides have been studied by 1H, 19F NMR, X-ray diffraction, DSC and impedance spectroscopy. The types of ion motions in the fluoride and ammonium sublattices of the fluorides have been determined in temperature range of 150–450 K and their activation energy was estimated. The presence of order-disorder phase transition in these fluorides in the temperature range of 400–450 K with the formation of metastable high-temperature β–modifications in which diffusion of fluoride and ammonium ions is the dominant type of ionic motion is established. The values of conductivity at 453 K [(~ 9.4–6.6) × 10–3 S/cm] indicate that the studied fluorides belong to the class of superionic conductors. |
| Databáze: | OpenAIRE |
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