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Electron Ream-Induced Phase Transformation In MgA1204 SPINEL

Published online by Cambridge University Press:  26 February 2011

S.J. Shaibani and
S.N. Buckley
S.J. Shaibani
Affiliation:
Department of Metallurgy, University of Oxford, Parks Road, Oxford, England
S.N. Buckley
Affiliation:
Materials Development Division, AERE Harwell, Didcot, Oxfordshire, England
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Abstract

Bombardino stoichiometric MgAl204 spinel at elevated temperatures with hiqh energy electron beams ciradually converts the irradiated area into γ-alumina. This phase transformation, which involves the diffusion of maginesium out of the irradiated area, shrinks the oxygen ion sublattice, thereby generating internal stresses which cause localised crystal fractures.

Three categories of crack are observed:type 1, the majority, are straiciht and lie at the centre of the irradiated area; type 3 are circular and they are located near the edge of the irradiated area in the spinel matrix: and, type 2 are hybrids. A quantitative model which explains the development of all types of crack is presented.

The proportion of γ-alumina produced, the fractional loss of magnesium and the extent of crackino are found to depend on the electron beam energy, the electron dose, the beam profile and the irradiation temperature.

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References

REFERENCES

1. Buckley, S.N., unpublished work (1983).Google Scholar
2. Pells, G.P. and Phillips, D.C., J. Nucl. Mat., 80, 207 (1979).CrossRefGoogle Scholar
3. Pells, G.P. and Phillips, D.C., J. Nucl. Mat., B1, 215 (1979).CrossRefGoogle Scholar
4. Shikama, T. and Pells, G.P., Phil. Mao. A, 47, 79 (1983).Google Scholar
5. Pells, G.P. and Shikama, T., Phil. Mag. A, 7M, 779 (1983).CrossRefGoogle Scholar
6. Veblen, D.R. and Buseck, P.R., Proc. 41st ETY.S.A., edited by Bailey, G.W. (1983), p. 350.Google Scholar
7. Lorimer, P. and Champness, P.E., in High Voltage Electron Microscopy, edited by Swann, P.R., Humphreys, C.J. and Goringe, M.J. (Academic Press, London, 1974), p. 301.Google Scholar
8. Hlhite, T.J. and Hyde, B.G., Am. Min., 68, 1009 (1983).Google Scholar
9. Lee, W.E., Mitchell, T.E. and HeuieF, A.H., Radiat. Eff. (to be published, 1985).Google Scholar
10. Cater, E.D. and Buseck, P.R., Ultramicroscopy (to be published, 1985).Google Scholar
11. Ruckley, S.N., Proc. 11th Symp. on Fusion Technology, Varese, Italy, September 24-28, 1984 (Pergamon Press, Oxford, 1984), Volume 2, p. 1011.Google Scholar
12. Shaibani, S.d., Buckley, S.N. and Jenkins, M.L., presented at 3rd Int. Coof. on Radiation Effects in Insulators, Guildford, England, July 15-10', 1QR5. To be published in Radiat. Eff.Google Scholar
13. Verwey, E.J.W., J. Kristalloor., A91, 65 (1935).Google Scholar
14. Verwey, E.J.W., Z. Kristallogr., A7T, 317 (1935).CrossRefGoogle Scholar
15. Handbook of Chemistry and PhysiCs-55th ed., edited by Weast, R.C. (Chemical Rubber Company, Clevelnd, Ohio, 1974).Google Scholar
16. Schmocker, U. and Waldoer, F., J. Phys. C, 9, L235 (1976).CrossRefGoogle Scholar
17. Buckley, S.N., Harwell Report AERE-R 117157, Chapter 3 (1985).Google Scholar
18. Buckley, S.N. and Shaibani, S.J., Harwell Report (to be published, 1985).Google Scholar