Nonlinear interdiffusion in binary nanometer-scale multilayers submitted to thermal annealing

The concentration profile in binary A-B nanometer-scale multilayers submitted to thermal annealing was calculated based on the Martin's kinetic discrete model for one-dimension nonlinear interdiffusion by a diffusion asymmetry coefficient m' and an ordering energy V between A and B atoms. With decreasing the diffusion asymmetry coefficient m' from 0 to - 6, the concentration profile of the multilayers deviated from symmetrical distribution, and their interfaces became sharp and shifted towards the side of the sublayer with lower pair interaction energy. The difference of diffusion coefficient of A and B atoms caused by the diffusion asymmetry coefficient m' led to the difference of net fluxes of A and B atoms in the multilayers. When the ordering energy V changed from - 0.001 eV to - 0.05 eV, change in the concentration profile and interface structure was same for the multilayers with a given diffusion asymmetry coefficient m', but the calculated diffusion time decreased correspondently. The lower ordering energy V makes the A and B atoms aggregating more easily during the interdiffusion. It is found that the nonlinear interdiffusion of a series of binary nanometer-scale multilayers can be characterized by the diffusion asymmetry coefficient m' and the ordering energy V, to explore the solid state reaction between the sublayers of nanometer-scale multilayers