The growth kinetics of an amorphous interlayer, which was formed by solid-state diffusion in ultra-high vacuum-deposited polycrystalline Gd thin films on (001)Si, were investigated by using cross-sectional transmission electron microscopy. The growth of the interlayer was found to obey a linear law at first. The growth then slowed down and deviated from the linear law. The results clearly indicated that the growth in the early stages was consistent with an interface reaction-controlled growth model rather than being diffusion-limited. The activation energy for the linear growth, and the maximum thickness, were about 0.37eV and 6.6nm, respectively. Following the growth of the amorphous interlayer, epitaxial hexagonal GdSi2 formed at the interlayer/(001)Si interface at 225C and hampered further growth.

Growth kinetics of amorphous interlayers by solid-state diffusion in ultra-high vacuum deposited polycrystalline Gd thin films on (001)Si J.C.Chen, G.H.Shen, L.J.Chen: Journal of Applied Physics, 1998, 84[11], 6083-7