Paper eintragenThe effects of annealing upon tri-layer thin films which consisted of amorphous Ge and polycrystalline Sb layers were studied by means of  in situ  heating in a transmission electron microscope. The results showed that reactions were triggered at the grain boundaries of the crystalline Sb layer and were accompanied by crystallization of the Ge and by the diffusion of Sb away from the grain boundaries. The broadening of the reacted region closely obeyed a square-root of time dependence. The data indicated grain-boundary diffusion coefficients which were 2 orders of magnitude higher along the grain boundaries than across them. The value across the grain boundaries was 2 orders of magnitude higher than the reported diffusivity of Sb in crystalline Ge, as extrapolated to the temperatures which were used in the present work.

A.K.Petford-Long, R.C.Doole, C.N.Aonso: Philosophical Magazine A, 1996, 74[4], 907-18