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Title: Sol-gel-fluorination synthesis of amorphous magnesium fluoride

Abstract

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.

Authors:
 [1];  [1];  [1];  [2];  [3]
  1. Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str.2, 12489 Berlin (Germany)
  2. Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str.2, 12489 Berlin (Germany). E-mail: erhard.kemnitz@chemie.hu-berlin.de
  3. Department of Chemistry, University of Glasgow, Glasgow (United Kingdom)
Publication Date:
OSTI Identifier:
20784917
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 179; Journal 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)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALKOXIDES; DESORPTION; FLUORINATION; HEAT TREATMENTS; MAGNESIUM FLUORIDES; NANOSTRUCTURES; NONAQUEOUS SOLVENTS; NUCLEAR MAGNETIC RESONANCE; SOL-GEL PROCESS; SURFACE AREA; SYNTHESIS; THERMAL ANALYSIS; THIN FILMS; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Krishna Murthy, J., Gross, Udo, Ruediger, Stephan, Kemnitz, Erhard, and Winfield, John M. Sol-gel-fluorination synthesis of amorphous magnesium fluoride. United States: N. p., 2006. Web. doi:10.1016/j.jssc.2005.11.033.
Krishna Murthy, J., Gross, Udo, Ruediger, Stephan, Kemnitz, Erhard, & Winfield, John M. Sol-gel-fluorination synthesis of amorphous magnesium fluoride. United States. doi:10.1016/j.jssc.2005.11.033.
Krishna Murthy, J., Gross, Udo, Ruediger, Stephan, Kemnitz, Erhard, and Winfield, John M. Wed . "Sol-gel-fluorination synthesis of amorphous magnesium fluoride". United States. doi:10.1016/j.jssc.2005.11.033.
@article{osti_20784917,
title = {Sol-gel-fluorination synthesis of amorphous magnesium fluoride},
author = {Krishna Murthy, J. and Gross, Udo and Ruediger, Stephan and Kemnitz, Erhard and Winfield, John M.},
abstractNote = {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.},
doi = {10.1016/j.jssc.2005.11.033},
journal = {Journal of Solid State Chemistry},
number = 3,
volume = 179,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
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