Results for As diffusion in polycrystalline material, during annealing (900C, 0.25h), were explained by means of a new model which took account of the different diffusion rates in grains and in grain boundaries. The model was also divided into early and late stages. The former indicated that grain growth was the main mechanism for As transfer from the grains to the boundaries. The late-stage model suggested that grain growth could be ignored, and analytical solutions for the As concentrations were derived.

A.G.O'Neil, C.Hill, J.King, C.Please: Journal of Applied Physics, 1988, 64[1], 167-74