Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-25T17:49:56.130Z Has data issue: false hasContentIssue false

Crystallization Kinetics of Rutile Formation from Amorphous Titania Films

Published online by Cambridge University Press:  21 February 2011

M.D. Wiggins
Affiliation:
Materials Department and The Laboratory for Surface Studies, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, WI 53201
M.C. Nelson
Affiliation:
Materials Department and The Laboratory for Surface Studies, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, WI 53201
C.R. Atta
Affiliation:
Materials Department and The Laboratory for Surface Studies, University of Wisconsin-Milwaukee, P.O. Box 784, Milwaukee, WI 53201
Get access

Abstract

Titania films with two types of phase composition were sputter deposited on fused silica substrates: Type (I) amorphous+anatase+rutile and Type (II) amorphous+rutile. These films were subjected to various annealing procedures in air. We studied three relevant transitions: 1) amorphous→crystalline (anatase and rutile) at temperature <800 °C, 2) amorphous→mitile at an temperatures, and 3) anatase→rutile in the 750–800 °C temperature range.

X-ray diffraction was used for phase identification and crystallographic orientation. The films had a preferred orientation, with (101) anatase and/or (110) rutile planes parallel to the substrate. The activation energy for the amorphous-to-rutile transformation was 0.3 eV. The anatase-to-rutile transformation occurring at 750 °C was modelled using the Avrami relation, which yielded an exponent of unity.

From the results of this study, we propose a model for titania crystallization in which site saturation of rutile and/or anatase nuclei already exists in the as-deposited film. Further crystallization upon annealing occurs by one dimensional growth of these nuclei into the amorphous material. If no anatase seeds exist in the as-deposited material, then no anatase will form upon annealing, indicating again that no new nuclei are formed during annealing. In this manner, highly oriented rutile titania films can be produced at temperature below the bulk anatase-to-rutile transformation temperature (750 °C).

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Clark, R.J.H., The Chemistry of Titanium and Vanadium. Elsevier Pub. Co., New York, 1968, p. 266.Google Scholar
2 See, for example: Kosuge, K.. Chemistry of Non-Stoichiometric Compounds. Oxford University Press, New York, 1994, pp. 115139.Google Scholar
3 Hsu, L.S., Rujkorakarn, R., Sites, J.R., and She, C.Y., J. Appl. Phys. 59, 3475 (1986).Google Scholar
4 Eastman, J.A., J. Appl. Phys. 75, 770 (1994).Google Scholar
5 Wiggins, M.D., Nelson, M.C., and Aita, C.R., J. Vac. Sci. Technol. A, in press.Google Scholar
6 DeVries, R.C. and Roy, Rustum, Am. Ceram. Soc. Bull. 33, 370 (1954).Google Scholar
7 Aita, C.R., J. Vac. Sci. Technol. A 11, 1540 (1993).Google Scholar
8 Kingery, W.D., Bowen, H.K., and Uhlmann, D.R.. Introduction to Ceramics. John Wiley & amp; Sons, Inc., New York, 1960, p. 240.Google Scholar
9 Gawlak, C.J. and Aita, C.R., J. Vac. Sci. Technol. A, 1, 415 (1983).Google Scholar
10 Avrami, M., J. Chem. Phys. 7, 1103 (1939).Google Scholar
11 Tu, K.N., Mayer, J.W., and Feldman, L.C., Electronic Thin Film Science. Macmillan Pub. Co., 1992, pp. 269274.Google Scholar
12 Christian, J.W., The Theory of Transformation in Metals and Alloys. 2nd Edition, Pergamon Press, 1975, pp. 528542.Google Scholar
13 Ranganathan, S. and von Heimendahl, M., J. Materials Science, 16 2401 (1981).Google Scholar