Many investigations of films grown on planar substrates at higher temperatures were accompanied by interdiffusion of atomic species across the planar interface from the substrate into the film and from the film into the substrate. In the present work, a new analysis was presented so that the concentration profiles of the diffusing species with different diffusion coefficients were determined. The analysis was carried out using the mathematical method of continuous distribution of diffusing sources in the two phases. The two boundary conditions in the form of continuity of flux and concentration at the interface were used to solve for the two

distribution functions. These results were used to solve for the concentration profiles resulting from the mass diffusion in the two-phase medium. Application of the solution to a bilayer system with a planar interface and different diffusion coefficients in the adjoining phases was provided to illustrate the use of this method to several situations.

Diffusion at a Planar Interface using Continuous Distribution of Sources. K.Jagannadham: Journal of Applied Physics, 2009, 105[2], 023504