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Melting and possible amorphization of Sn and Pb in Ge/Sn and Ge/Pb mechanically milled powders

Published online by Cambridge University Press:  31 January 2011

J. S. C. Jang
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695
C. C. Koch
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695
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Abstract

Mixtures of Ge–Sn and Ge–Pb powders were ball-milled to form a fine dispersion. After 32 h of milling the average diameter of the hard Ge particles embedded in the Sn (or Pb) matrix was about 10 nm. As the Ge concentration was increased in each system, the melting point, TM, and the enthalpy of fusion, ΔHM, of Sn (or Pb) decreased. Only small changes in ΔTM and ΔHM were observed after heating cycles in the DSC to above the melting point. The melting endotherm measured by DSC disappeared for Ge-rich compositions (88 and 95 vol.% Ge for Ge–Sn; 93.5 vol.% Ge for Ge–Pb). It is suggested that atomic disorder/melting is nucleated at the Ge/Sn (or Ge/Pb) interfaces and the melting point and enthalpy of fusion decrease as the interfacial area increases. When the Ge volume reaches a value where essentially all the Sn (or Pb) atoms are adjacent to the Ge particle surfaces, the Sn is in a disordered–perhaps amorphous–state such that no melting transition is observed.

Type
Articles
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

1Boyer, L.L., Phase Transitions 5, 1 (1985).Google Scholar
2Lindemann, F. A. Von, Z. Phys. 11, 609 (1910).Google Scholar
3Gorecki, T., Z. Metallkd. 65, 426 (1974).Google Scholar
4Cotterill, R. M. J., Jensen, E. J., and Kristen, W. D., Phys. Lett. A 44, 127 (1973).CrossRefGoogle Scholar
5Born, M., J. Chem. Phys. 7, 591 (1939).CrossRefGoogle Scholar
6Couchman, P. R. and Jesser, W. A., Phil. Mag. 35 787 (1977).CrossRefGoogle Scholar
7Takagi, M., J. Phys. Soc. Jpn. 9, 359 (1954).CrossRefGoogle Scholar
8Wronski, C.R., Brit. J. Appl. Phys. 18, 1731 (1967).CrossRefGoogle Scholar
9Buffat, P. and J. Borel, Phys. Rev. A 13, 2287 (1976).Google Scholar
10Allen, G.L., Gile, W.W., and Jesser, W. A., Acta Metall. 28 1695 (1980).CrossRefGoogle Scholar
11Allen, G.L., Boyles, R.A., Gile, W.W., and Jesser, W.A, Thin Solid Films 144, 297 (1986).Google Scholar
12Saka, H., Nishikawa, Y., and Imura, T., Phil. Mag. A 57, 895 (1988).Google Scholar
13Willens, R. H., Kornblit, A., Testardi, L.R., and Nakahara, S., Phys. Rev. B 25, 290 (1982); G. Devaud and R. H. Willens, Phys. Rev. Lett. 57, 2683 (1986).CrossRefGoogle Scholar
14Koch, C.C., Jang, J.S.C., and Gross, S.S., J. Mater. Res. 4, 557 (1989).Google Scholar
15Turnbull, David, Harvard University (private communication), December 1988.Google Scholar
16Johnson, W. L., Prog, in Mater. Sci. 30, 81 (1986).Google Scholar
17 “Solid State Amorphizing Transformations”, Proc. of Conf. on Solid State Amorphizing Transformations, Los Alamos, NM, August 10–13, 1987, edited by Schwarz, R. B. and Johnson, W. L.; also in J. Less-Common Metals 140, 1–399 (1988).Google Scholar
18Ermakov, A. E., Yurchikov, E. E., and Barinov, Y. A., Phys. Met. Metall. 52, 50 (1981).Google Scholar
19Schwarz, R. B. and Koch, C. C., Appl. Phys. Lett. 49, 146 (1986).CrossRefGoogle Scholar
20Luzzi, D. E. and Meshii, M., Res. Mechanica 21, 207 (1987).Google Scholar
21Koch, C. C., Jang, J. S. C., and Lee, P.Y., in “New Materials by Mechanical Alloying Techniques”, edited by Arzt, E. and Schultz, L., Proc. DGM Conf., Calw-Hirsau, October 1988, DGM Informationsgesellschaft, Oberursel, 1989.Google Scholar
22Jang, J. S. C. and Koch, C. C., J. Mater. Res. (in press).Google Scholar