The mobility of substitutional B in single crystals of graphite was measured by using an etch-decoration method which made it possible to locate individual B atoms by electron microscopy. The mobility of B was not very sensitive to the B concentration, for B/C values between 10-2 and 10-8. The diffusion constants between 1700 and 2400C were described by:

D(cm2/s) = 6320 exp[-157000/RT]

for motion parallel to the layer planes and by:

D(cm2/s) = 7.1 exp[-153000/RT]

for motion perpendicular to the layers.

G.Hennig: The Journal of Chemical Physics, 1965, 42[4], 1167-72