The use of hydrothermal procedures to synthesize NASICON and some comments on the stoichiometry of NASICON phases
| Autor: | W. Wang, M.A. Subramanian, Abraham Clearfield, P. Jerus |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Materials science
Mineralogy General Chemistry Condensed Matter Physics Hydrothermal circulation Crystallography chemistry.chemical_compound Zirconium phosphate chemistry Phase (matter) Yield (chemistry) Fast ion conductor General Materials Science Orthorhombic crystal system Stoichiometry Monoclinic crystal system |
| Zdroj: | Solid State Ionics. :895-902 |
| ISSN: | 0167-2738 |
| DOI: | 10.1016/0167-2738(83)90108-x |
| Popis: | NASICON was prepared by a two step process. In the first step zirconium phosphate an Na 4 SiO 4 are treated hydrothermally at 300°C. This produced a hydrated phase with approximate composition Na 4 Zr 2 Si 2.25 P 1.8 O 15 ·H 2 O which could be indexed on the basis of an orthorhombic cell with a=8.743(1), b=10.317(4), c=7.317(1) A . Upon heating this orthorhombic phase to 1100°C, P 2 O 5 splits out to yield monoclinic NASICON of composition Na 3.3 Zr 1.65 Si 1.9 P 1.1 O 11.5 . This formula reflects both a deficiency of ZrO 2 and Zr 4+ , compensated by Na + for charge balance, over that required by Na 1+x Zr x2 Si x P 3−x O 12 . It is proposed that both a NASICON series of the latter type and the defect type described in this paper exist, with the stoichiometric one being unstable and regarding to the defect structure upon heating. |
| Databáze: | OpenAIRE |
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