In-diffusion and out-diffusion of oxygen from a composite containing random traps

In this paper, we investigate oxygen in-diffusion and out-diffusion with respect to a cermet composite where oxygen segregates at the interface between the metal matrix phase and the ceramic oxide phase. This phenomenological diffusion problem is treated by overlaying it with a fine-grained lattice that was addressed using a Lattice Monte Carlo method and a little-known exact expression for the lattice-based effective diffusivity in the presence of random traps. It is shown that there is very good agreement for the oxygen concentration depth profiles between the Monte Carlo results and the exact expression.