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Observation of the Phase-Boundary Controlled Formation of NiA12O4 From a Single-Crystal NiO Thin Film and a Single-Crystal α-A12O3 Substrate

Published online by Cambridge University Press:  21 February 2011

Paul G. Kotula
Affiliation:
Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave. S.E., Minneapolis, MN 55455
C. Barry Carter
Affiliation:
Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Ave. S.E., Minneapolis, MN 55455
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Abstract

High-quality NiO thin films have been grown on single-crystal α-A12O3 substrates ((0001) orientation) by pulsed-laser ablation, forming essentially the idealized solid-state reaction geometry-a single-crystal film in intimate contact with a single-crystal substrate. These reaction couples have been characterized by cross-section transmission electron microscopy and scanning electron microscopy both before and after being heated in air to induce the solid-state reaction (i.e., Ni-spinel formation). The NiO films consisted of two twin variants which were found to conform to the underlying substrate surface steps. The substrate surface steps were produced by heat-treating the substrates prior to thin film deposition. Using this reaction geometry, it has been found that the initial reaction of the spinel takes place where twin boundaries in the NiO films meet the substrate. The initial reaction corresponds to the nucleation of the spinel. This interpretation is supported by the fact that the reaction proceeded faster up the NiO twin boundaries than elsewhere along the reaction layer (i.e., nucleation of the spinel is easier at twin boundaries in the NiO film). Scanning electron microscopy has been used with the present thin-film reaction geometry to measure reaction layer width along interfaces up to 2 mm long.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

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References

1. Sockel, H. G. and Schmalzried, H., Mat. Sci. Res. 3, 6173 (1966).Google Scholar
2. Carter, C. B. and Schmalzried, H., Phil. Mag. 52, 207224 (1985).CrossRefGoogle Scholar
3. Pettit, F. S., Randklev, E. H. and Felten, E. J., J. Am. Ceram. Soc. 49, 199203 (1966).CrossRefGoogle Scholar
4. Minford, W. J. and Stubican, V. S., J. Am. Ceram. Soc. 57, 363367 (1974).CrossRefGoogle Scholar
5. Hirota, K. and Komatsu, W., J. Am. Ceram. Soc. 60, 105107 (1977).CrossRefGoogle Scholar
6. Thirsk, H. R. and Whitmore, E. J., Trans. Farad. Soc. 36, 565574 (1940).CrossRefGoogle Scholar
7. Roos, G. de, Wit, J. H. W. de, Fluit, J. M., Geus, J. W. and Velthuizen, R. P., Surf. Interface Anal. 5, 119131 (1983).CrossRefGoogle Scholar
8. Simpson, Y. K., Colgan, E. G. and Carter, C. B., J. Am. Ceram. Soc. 70, C149–C151 (1987).CrossRefGoogle Scholar
9. Schmalzried, H., Solid-State Reactions, Verlag Chemie, (1981)Google Scholar
10. Simpson, Y. K., Colgan, E. G. and Carter, C. B., Mat. Res. Soc. Symp. Proc. 94, 299304 (1987).CrossRefGoogle Scholar
11. Susnitzky, D. W. and Carter, C. B., J. Am. Ceram. Soc. 75, 24632478 (1992).CrossRefGoogle Scholar
12. Kotula, P. G. and Carter, C. B., Mat. Res. Soc. Symp. Proc. 285, 373379 (1993).CrossRefGoogle Scholar
13. Kotula, P. G. and Carter, C. B., Proc. 2nd Int. Conf. on Laser Ablation, AIP Conference Proceedings 288, 231236 (1993).Google Scholar
14. Kotula, P. G. and Carter, C. B., in Proceedings of the 51st Annual Meeting of the Microscopy Society of America, edited by Bailey, G. W. and Rieder, C. L. (San Francisco Press, Inc., Cincinatti, OH, 1993), p. 11201121.Google Scholar
15. Kotula, P. G., Mallamaci, M. P. and Carter, C. B., Unpublished work. (1993).Google Scholar
16. Susnitzky, D. W., Summerfelt, S. R. and Carter, C. B., Unpublished work (1988).Google Scholar
17. Li, D. X., Pirouz, P., Heuer, A. H., Yadavalli, S. and Flynn, C. P., Phil. Mag. 65, 403425 (1992).CrossRefGoogle Scholar
18. Lee, W. E. and Lagerlof, K. P. D., J. Electron Microsc. Tech. 2, 247258 (1985).CrossRefGoogle Scholar
19. Carter, C. B., Elgat, Z. and Shaw, T. M., Phil. Mag. A 55, 2138 (1987).CrossRefGoogle Scholar