Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-20T06:57:39.337Z Has data issue: false hasContentIssue false

Ground Based Studies for the Space Processing of Lead-Tin-Telluride

Published online by Cambridge University Press:  15 February 2011

Roger K. Crouch
Affiliation:
NASA Langley Research Center, Hampton, Virginia, 23665, USA
A. L. Fripp
Affiliation:
NASA Langley Research Center, Hampton, Virginia, 23665, USA
W. J. Debnam
Affiliation:
NASA Langley Research Center, Hampton, Virginia, 23665, USA
I. O. Clark
Affiliation:
NASA Langley Research Center, Hampton, Virginia, 23665, USA
F. M. Carlson
Affiliation:
KRAR, Inc., Bagdad Road, Potsdam, New York, 13676, USA
Get access

Abstract

This paper summarizes the results of a series of studies dealing with crystal growth from the melt and in particular, the growth of the narrow bandgap semiconductor PbSnTe by the Bridgman technique. Theoretical calculations have shown that for low Prandtl number fluids such as semiconductors, convection has no effect on the temperature field in the melt but has a significant effect on the compositional field. They also show that convective flow will exist in a Bridgman growth system on Earth, even in the “thermally stable” configuration. Measurements of the specific heat have been made up to temperatures of 722° C. The thermal diffusivity has been measured up to 1010° C which includes values for the melt. The interdiffusion coefficients for PbTe and SnTe in the melt have been determined. A technique has been developed and tested which provides a vacuum tight quartz ampoule with electrical feedthroughs for interface demarcation studies during the Bridgman growth. Analysis of crystals grown has indicated that the PbSnTe system is solutally unstable and the distribution of SnTe in the crystal, after an anomalous first to freeze region, follows that predicted by Pfann for convection controlled growth. Studies of the amount of supercooling in PbSnTe indicates that this may explain an anomalous composition distribution in the first to freeze region of an unseeded growth.

Type
Research Article
Copyright
Copyright © Materials Research Society 1982

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.Parker, S. G. and Johnson, R. E., in Preparation and Properties of Solid State Materials, ed. Wilcox, W. R. (Marcel Dekker, New York) to be published.Google Scholar
2.Crouch, R. K. et al. , This Volume, to be published.Google Scholar
3.Clark, I. O. et al. , J. Electrochem. Soc., to be published.Google Scholar
4.Lichtensteiger, M., Witt, A. F. and Gatos, H. C., J. Electrochem. Soc.Solid State Science, 118, 1013 (1971).Google Scholar
5.Crouch, R. K. et al. , J. Crystal Growth, to be published (1981).Google Scholar
6.Holmes, D. E., Ph.D. Thesis, Mass. Inst. Tech., “Morphological Stability of the Solid-Liquid Interface,” (1977).Google Scholar
7.Pfann, W. G., Zone Melting (John Wiley and Sons, New York 1966) P. 11.Google Scholar
8.Tiller, W. A. et al. , Acta Metallurgica, 1, 428 (1953).Google Scholar
9.Pfann, W. G., Trans. AIME, 194, 747 (1952).Google Scholar
10.Fripp, A. L. et al. , Materials Research Society Symposium, Boston, Massachusetts (November 1981).Google Scholar