Diffusion coefficients were deduced, from a concentration distribution which exhibited an exponential profile, by using the Boltzmann-Matano technique. It was found that the relative diffusion coefficient was given by:

Dc/Do = A(1 - ln[C]) + (1/C)(1-A)

where C was the relative concentration, Do was the diffusion coefficient for C = 1, and A was a constant. The results were applied to the cases of Ga and As diffusion in a ZnSe film which was grown onto a GaAs substrate. It was noted that DoGa was equal to 2.92 x 10-11cm2/s and that DoAs was equal to 3.04 x 10-11cm2/s. The value of DGa at relatively low concentrations (near to the film surface) approached the diffusion coefficient that had been deduced from a complementary error function distribution.

T.Muranoi: Thin Solid Films, 1991, 197[1-2], 393-6