First Phase Formation Kinetics in the Reaction of Nb/Al


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.

This is a preview of subscription content, access via your institution.


  1. 1.

    J.L. Jorda, R. Flukiger, and I. Muller,. J. of the Less Common Metals 75, 22(1980).

    Article  Google Scholar 

  2. 2.

    K. Barmak, K.R. Coffey, D.A. Rudman, and S. Foner, J. Appl. Phys. 67, 7313 (1990).

    CAS  Article  Google Scholar 

  3. 3.

    R. Bormann, H.U. Krebs, and A.O. Kent, Adv. Cryo. Eng. ICMC 32, 1041 (1986).

    CAS  Google Scholar 

  4. 4.

    Y. Im, P. Johnson, L. McKnclly, Jr., and J.W. Morris, J. of the Less Common Metals 139, 87 (1988).

    CAS  Article  Google Scholar 

  5. 5.

    K.R. Coffey, L.A. Clevenger, K. Barmak, D.A. Rudman, and C.V. Thompson, Appl. Phys. Lett. 55, 852 (1989).

    CAS  Article  Google Scholar 

  6. 6.

    K. Barmak, K.R. Coffey, D.A. Rudman, and S. Foncr, J. Appl. Phys. 67, 3780 (1990).

    CAS  Article  Google Scholar 

  7. 7.

    K.R. Coffey, Ph.D Thesis, Massachusetts Institute of Technology, 1989.

  8. 8.

    R. Bormann (private communication).

  9. 9.

    P. G. Boswell, J. Thermal Anal. 18, 353 (1980).

    CAS  Article  Google Scholar 

  10. 10.

    G. Slama and A. Vignes, J. of the Less Common Metals 29, 189 (1972); 23, 375 (1971); 24, 1 (1971); 29, 189 (1972).

    CAS  Article  Google Scholar 

  11. 11.

    E. Ma, C.V. Thompson, and L.A. Clevenger, presented at the 1990 MRS Fall Meeting, Boston, MA, 1990 (unpublished).

  12. 12.

    J.W. Cahn, Acta Met. 4, 449 (1956).

    CAS  Article  Google Scholar 

  13. 13.

    J.W. Christian, The Theory of Transformations in Mctals and Alloys, 2nd eds. (Pergamon Press, Oxford, 1975), p. 441.

    Google Scholar 

  14. 14.

    K. Barmak, Ph.D. Thesis, Massachusetts Institute of Technology, 1989.

Download references


K.C. Russell is acknowledged for helpful discussions. Support provided by: DOE BES DE-FG02-85ER45206, CMSE/NSF DMR-8802613, ATT, andl IBM Fellowships

Author information



Corresponding author

Correspondence to K. R. Coffey.

Additional information

Contribution by U.S. Government, not subject to copyright

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Coffey, K.R., Barmak, K., Rudman, D.A. et al. First Phase Formation Kinetics in the Reaction of Nb/Al. MRS Online Proceedings Library 230, 55–60 (1992).

Download citation