Sol-gel-fluorination synthesis of amorphous magnesium fluoride
- Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str.2, 12489 Berlin (Germany)
- Department of Chemistry, University of Glasgow, Glasgow (United Kingdom)
The sol-gel fluorination process is discussed for the reaction of magnesium alkoxides with HF in non-aqueous solvents to give X-ray amorphous nano-sized magnesium fluoride with high surface areas in the range of 150-350 m{sup 2}/g (HS-MgF{sub 2}). The H2 type hysteresis of nitrogen adsorption-desorption BET-isotherms is indicative for mesoporous solids. A highly distorted structure causes quite high Lewis acidity, shown by NH{sub 3} temperature-programmed desorption (NH{sub 3}-TPD) and catalytic test reactions. XPS data of amorphous and conventionally crystalline MgF{sub 2} are compared, both show octahedral coordination at the metal site. Thermal analysis, F-MAS NMR- and IR-spectroscopy give information on composition and structure of the precursor intermediate as well as of the final metal fluoride. The preparation of complex fluorides, M{sup +}MgF{sub 3} {sup -}, by the sol-gel route is reported. From the magnesium fluoride gel of the above process thin films for optical application are obtained by, e.g., spin coating.
- OSTI ID:
- 20784917
- Journal Information:
- Journal of Solid State Chemistry, Vol. 179, Issue 3; Other Information: DOI: 10.1016/j.jssc.2005.11.033; PII: S0022-4596(05)00570-0; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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