Ion-beam sputtering was used to study impurity diffusion in single crystals at 553 to 838K. It was found that the diffusivities ranged from 5 x 10-21 to 9.67 x 10-16m2/s, and could be described by:

D (cm2/s) = 3.6 x 10-1 exp[-1.75(eV)/kT]

These data were in good agreement with published results which were obtained by using conventional sectioning techniques at higher temperatures.

H.Mehrer, D.Weiler: Zeitschrift für Metallkunde, 1984, 75[3], 203-5