The diffusion of Si in thin films of Al was measured by using a configuration with in-diffusion from 2 constant sources to a specimen of finite thickness. Electron microprobe techniques were used to measure the Si distribution. The results for 475 to 550C could be described by:

D (cm2/s) = 8.3 x 10-3 exp[-0.81(eV)/kT]

The values were much higher than those measured in wrought Al. The Si transport was unaffected by Al grain size ranging from 0.0003 to 0.0008mm.

A.Paccagnella, P.Ottaviani, P.Fabbri, G.Ferla, G.Queirolo: Thin Solid Films, 1985, 128[3-4], 217-23