Formation of Chemical Compound Layer at the Interface of Initial Substances A and B with Dominance of Diffusion of the A Atoms

Authors: Pavlo Selyshchev, Samuel Akintunde

Abstract:

A theoretical approach to consider formation of chemical compound layer at the interface between initial substances A and B due to the interfacial interaction and diffusion is developed. It is considered situation when speed of interfacial interaction is large enough and diffusion of A-atoms through AB-layer is much more then diffusion of B-atoms. Atoms from A-layer diffuse toward B-atoms and form AB-atoms on the surface of B-layer. B-atoms are assumed to be immobile. The growth kinetics of the AB-layer is described by two differential equations with non-linear coupling, producing a good fit to the experimental data. It is shown that growth of the thickness of the AB-layer determines by dependence of chemical reaction rate on reactants concentration. In special case the thickness of the AB-layer can grow linearly or parabolically depending on that which of processes (interaction or the diffusion) controls the growth. The thickness of AB-layer as function of time is obtained. The moment of time (transition point) at which the linear growth are changed by parabolic is found.

Keywords: Phase formation, Binary systems, Interfacial Reaction, Diffusion, Compound layers, Growth kinetics.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1093239

References:

[1] H. Schmalzried Chemical Kinetics of Solids. Weinheim, New York, Basel, Cambridge, Tokyo: VCH, 1995, 433p.
[2] C.-D. Lien, M.-A. Nicolet and S.S. Lau, "Kinetics of silicides on Si(100) and evaporated silicon substrates” Thin Solid Films, vol. 143, pp. 63-72, 1986.
[3] U.R. Evans The Corrosion and Oxidation of Metals: Scientific Principles and Practical Applications London, England: Edward Arnold, 1960, 272 p.
[4] M. Wittmer and K.N. Tu, "On the Growth Kinetics and Diffusion Mechanism in Pd2Si," Rev. B., vol.27 pp.1173- 1983.
[5] C.S. Wei, J. Van der Spiegel, and J. J. "Santiago Growth Kinetics of Palladium Silicides Formed by Rapid Thermal Annealing,” J. Electrochem. Soc., vol.135(2), pp. 446-451; 1988.
[6] N.W. Cheung, M.A. Nicolet, M. Wittmer, C.A. Evans, T.T. Sheng, "Growth kinetics of Pd 2Si from evaporated and sputter-deposited films,” Thin Solid Films, vol.79, pp.51-60, 1981.
[7] R.W. Bower, D. Sigurd, R. Scott, "Formation kinetics and structure of Pd2Si films on Si,” Solid-State Electron, vol. 16, pp.1461–1471, 1973.
[8] D. Levy, A. Grob and J.P. Ponpon, "Formation of palladium Silicide by rapid thermal annealing,” Appl. Phys., vol. A35, 141-144, 1984.