Lattice diffusion of impurity enhanced by a surface heterogeneous reaction

It is shown that a heterogeneous surface reaction affects impurity distribution in the bulk of a solid body. An analytic expression for the concentration of crystal defects as a function of coordinate and reaction time and a diffusion equation in view of this expression were derived. Numerical simulation shows that the impurity concentration varies as ∼exp(-(x/σ)β. Analytic results were compared with experimental data for phosphorus diffusion upon forming nickel silicide.