Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-14T09:03:55.133Z Has data issue: false hasContentIssue false
  • English
  • Français

Velocity and Morphology Transition in Dendritic Growth

Published online by Cambridge University Press:  21 February 2011

E. Raz  and
A. Chait
E. Raz
Affiliation:
Nasa Lewis Research Center, Cleveland, OH. 44135
A. Chait
Affiliation:
Nasa Lewis Research Center, Cleveland, OH. 44135
Get access

Abstract

The growth velocity and morphology of crystals growing in a supercooled aqueous solution of ammonium chloride (28 wt%) with small amounts of copper sulfate (0.05 to-1 wt%) have been examined. For the [100] growth direction at low supercooling and for the [110] direction at greater supercooling the crystals start to grow slowly with a faceted interface. As the supercooling is continuously increased, the growth direction becomes [111]. Dendrites with pointed tips develop but continue to grow slowly. With further increase in supercooling, the velocity increases 20- to 40-fold and the tip shape changes from a cusp to a thin and almost paraboloid interface while the growth direction remains [111]. The velocity transition is gradual when the concentration is below 0.1 wt% but is sharper at higher concentrations. The transition temperature decreases with increasing copper sulfate concentration.

We postulate that the observed transition indicates a dynamic roughening phenomenon, where the supercooling; is sufficiently high to create many nucleation islands on the faceted interface. In this case the interface behaves as an atomically rough surface and dendrite growth occurs at an interface temperature that is below the equilibrium temperature.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 237: Symposium Ca – Interface Dynamics and Growth , 1991 , 131
Copyright
Copyright © Materials Research Society 1992

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

1. Ben-Jacob, E. and Garik, P., Nature 343, 523 (1990).Google Scholar
2. Chan, S.-K., Reimerand, H.H., Kahlweit, M., J. Cryst. Growth 32, 303 (1976).Google Scholar
3. Langer, J.S., Physicochem. Hydrodyn. 1, 41 (1980).Google Scholar
4. Lipton, J., Glicksman, M.E. and Kurz, W., Mater. Sci. Eng. 65, 57 (1984).Google Scholar
5. van Saaloos, W. and Gilmer, G. H., Phys. Rev. B 33, 4927 (1986).Google Scholar
6. Grossmann, B., Guo, H. and Grant, M., Phys. Rev. A 43, 1727 (1991).Google Scholar
7. Dougherty, A. and Gollub, J. P., Phys. Rev. A 38, 3043 (1988).Google Scholar
8. Maurer, J., Bouissou, P., Perrin, B. and Iabeling, P., Europhys Lett. 8, 68 (1989).CrossRefGoogle Scholar
9. Raz, E., Lipson, S.G. and Polturak, E., Phys. Rev. A 40, 1088 (1989).Google Scholar
10. Balibar, S., Gallet, F. and Rolley, E., J. Cryst. Growth 99, 46 (1990).Google Scholar
11. Raz, E., Lipson, S. G. and Ben-Jacob, E., J. Cryst. Growth 108, 637 (1991).Google Scholar
12. Raz, E., Lipson, S. G. and Ben-Jacob, E., unpublished.Google Scholar
13. Franck, J. P. and Jung, J., Physica 23D, 259 (1986).Google Scholar
14. Chernov, A. A., J. Cryst. Growth 24/25, 11 (1974).Google Scholar
15. Elwell, D., Zubeck, I. V., Feigelson, R. S. and Huggins, R. A., J. Cryst. Growth 29, 65 (1975).Google Scholar
16. Private comunicationGoogle Scholar
17. Yarnitzky, C.N., Analitical Chemistry 57, 2011 (1985).CrossRefGoogle Scholar