Nature of the chemical bond and prediction of radiation tolerance in pyrochlore and defect fluorite compounds

Lumpkin, G. R. and Pruneda, J. M. and Rios, S. and Smith, K. L. and Trachenko, K. and Whittle, K. R. and Zaluzec, N. J. (2007) Nature of the chemical bond and prediction of radiation tolerance in pyrochlore and defect fluorite compounds. Journal of Solid State Chemistry, 180 (4). pp. 1512-1518. DOI 10.1016/j.jssc.2007.01.028

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Abstract

The radiation tolerance of synthetic pyrochlore and defect fluorite compounds has been studied using ion irradiation. We show that the results can be quantified in terms of the critical temperature for amorphization, structural parameters, classical Pauling electronegativity difference, and disorder energies. Our results demonstrate that radiation tolerance is correlated with a change in the structure from pyrochlore to defect fluorite, a smaller unit cell dimension, and lower cation–anion disorder energy. Radiation tolerance is promoted by an increase in the Pauling cation–anion electronegativity difference or, in other words, an increase in the ionicity of the chemical bonds. A further analysis of the data indicates that, of the two possible cation sites in ideal pyrochlore, the smaller B-site cation appears to play the major role in bonding. This result is supported by ab initio calculations of the structure and bonding, showing a correlation between the Mulliken overlap populations of the B-site cation and the critical temperature.

Item Type: Article
Uncontrolled Keywords: 2007 AREP IA54 2007 P kot;
Subjects: 03 - Mineral Sciences
Divisions: 03 - Mineral Sciences
Journal or Publication Title: Journal of Solid State Chemistry
Volume: 180
Page Range: pp. 1512-1518
Identification Number: 10.1016/j.jssc.2007.01.028
Depositing User: Sarah Humbert
Date Deposited: 16 Feb 2009 13:03
Last Modified: 23 Jul 2013 10:07
URI: http://eprints.esc.cam.ac.uk/id/eprint/496

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