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First Phase Formation Kinetics in the Reaction of Nb/Al

Published online by Cambridge University Press:  26 July 2012

K. R. Coffey
Affiliation:
I.B.M., SSPD, 5600 Cottle Rd., San Jose, CA 95193
K. Barmak
Affiliation:
I.B.M., GTD, East Fishkill Facility, Hopewell Jct., NY 12533
D. A. Rudman
Affiliation:
N.I.S.T., 325 Broadway, Boulder, CO 80303
S. Foner
Affiliation:
N.M.L., M.I.T., Cambridge, MA 02039
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Abstract

Phase Formation kinetics in the reaction of Nb/Al multilaycred thin films were investigated using scanning calorimetry, x-ray diffraction, and transmission electron microscopy. The first phase to form upon annealing the Nb/Al layered structure is the NbAl3 intermetallic. Its formation is clearly identified by the calorimetry to be a two stage process, which has been modeled as the nucleation and three-dimensional growth to coalescence of the product phase in the plane of the initial interface, followed by the thickening of the product layer by one-dimensional growth perpendicular to the interface plane. For the initial reaction stage the reaction front velocity is higher than can be supported by diffusional transport within the lattice adjacent to the moving interface. Thus diffusion along nonequilibrium interfaces must be the growth mechanism. The large volume fraction consumed during the initial reaction stage indicates a lower nucleation site density than expected at a Nb/Al interface at local equilibrium, suggesting that the interface transport is reducing the driving force for nucleation.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

1. Jorda, J.L., Flukiger, R., and Muller, I.,. J. of the Less Common Metals 75, 22(1980).Google Scholar
2. Barmak, K., Coffey, K.R., Rudman, D.A., and Foner, S., J. Appl. Phys. 67, 7313 (1990).Google Scholar
3. Bormann, R., Krebs, H.U., and Kent, A.O., Adv. Cryo. Eng. ICMC 32, 1041 (1986).Google Scholar
4. Im, Y., Johnson, P., McKnclly, L. Jr., and Morris, J.W., J. of the Less Common Metals 139, 87 (1988).Google Scholar
5. Coffey, K.R., Clevenger, L.A., Barmak, K., Rudman, D.A., and Thompson, C.V., Appl. Phys. Lett. 55, 852 (1989).Google Scholar
6. Barmak, K., Coffey, K.R., Rudman, D.A., and Foncr, S., J. Appl. Phys. 67, 3780 (1990).Google Scholar
7. Coffey, K.R., Ph.D Thesis, Massachusetts Institute of Technology, 1989.Google Scholar
8. Bormann, R. (private communication).Google Scholar
9. Boswell, P. G., J. Thermal Anal. 18, 353 (1980).Google Scholar
10. Slama, G. and Vignes, A., J. of the Less Common Metals 29, 189 (1972); 23, 375 (1971); 24, 1 (1971); 29, 189 (1972).Google Scholar
11. Ma, E., Thompson, C.V., and Clevenger, L.A., presented at the 1990 MRS Fall Meeting, Boston, MA, 1990 (unpublished).Google Scholar
12. Cahn, J.W., Acta Met. 4, 449 (1956).Google Scholar
13. Christian, J.W., The Theory of Transformations in Mctals and Alloys, 2nd eds. (Pergamon Press, Oxford, 1975), p. 441.Google Scholar
14. Barmak, K., Ph.D. Thesis, Massachusetts Institute of -Tchnology, 1989.Google Scholar