Mountjoy, Gavin, Pickup, David M., Anderson, Ruth, Wallidge, Graham, Holland, Mark A., Newport, Robert J., Smith, Mark E. (2000) Changes in the Zr environment in zirconia-silica xerogels with composition and heat treatment as revealed by Zr K-edge XANES and EXAFS. Physical Chemistry Chemical Physics, 2 (10). pp. 2455-2460. ISSN 1463-9076. (doi:10.1039/a910300g) (KAR id:15927)
PDF
Language: English |
|
Download this file (PDF/4MB) |
Preview |
Request a format suitable for use with assistive technology e.g. a screenreader | |
Official URL: http://dx.doi.org/10.1039/a910300g |
Abstract
X-ray absorption spectroscopy at the Zr K-edge is an important technique for probing the environment of Zr. Here it is applied to zirconia-silica xerogels with composition 0.07 less than or equal to x less than or equal to 0.40, where x is the molar ratio Zr : (Zr + Si). Reference samples of crystalline ZrO2, ZrSiO4, BaZrO3 and liquid Zr n-propoxide were also examined. New XANES (X-ray adsorption near edge structure) results are presented for zirconia-silica xerogels, and compared with previous EXAFS (extended X-ray absorption fine structure) results. For high Zr contents (x = 0.4) there is a separate, amorphous ZrO2 phase, which before heat treatment is similar to Zr hydroxide, and after heat treatment at 750 degrees C is similar to an amorphous precursor of tetragonal ZrO2. For low Zr contents (x = 0.1) there is atomic mixing of Zr in the SiO2 network, and the environment of Zr is more similar to that in Zr n-propoxide compared to other reference samples. New in situ XANES and EXAFS results are presented for x = 0.1 xerogels heated at 250 degrees C. These clearly show that the Zr environment depends on ambient moisture in addition to heat treatment.
Item Type: | Article |
---|---|
DOI/Identification number: | 10.1039/a910300g |
Subjects: | Q Science |
Divisions: | Divisions > Division of Natural Sciences > Physics and Astronomy |
Depositing User: | J.M. Smith |
Date Deposited: | 08 May 2009 15:43 UTC |
Last Modified: | 05 Nov 2024 09:50 UTC |
Resource URI: | https://kar.kent.ac.uk/id/eprint/15927 (The current URI for this page, for reference purposes) |
- Link to SensusAccess
- Export to:
- RefWorks
- EPrints3 XML
- BibTeX
- CSV
- Depositors only (login required):