The sub-surface segregation of C in monocrystals was studied by using the 12C(d,p)13C nuclear reaction. The concentration depth profiles could be studied at a resolution of 0.0003mm to a depth of 0.0015 to 0.002mm, with a sensitivity of 20ppm[wt]C. Upon heating to above 150K, a sharp increase in the C signal was observed and was attributed to the diffusion of C from the bulk to the surface. It was deduced that the data could be described by:

D (m2/s) = 3 x 10-13 exp[-12(kJ/mol)/RT]

H.Kathrein, H.Wengeler, R.Knobel, F.Freund, G.Demortier, H.Gonska: High Temperatures – High Pressures, 1983, 15[3], 353-4