Films were radio-frequency sputtered onto the (100) surface of single crystals. These diffused into the substrate upon annealing at between 250 and 350C. The change in the concentration gradient was determined by means of Auger and ion sputtering techniques. The diffusivity could be described by:

D(cm2/s) = 1 x 10-13exp[-0.27(eV)/kT]

G.L.P.Berning, K.H.Yoon, G.Lewis, S.Sinharoy, L.L.Levenson: Thin Solid Films, 1977, 45[1], 141-5