Measurements were performed by using a surface ionization ion microscope. It was found that K diffusion on clean (112) surfaces was very anisotropic: diffusion along channels in [111]-type directions was faster than it was in the perpendicular [110]-type directions. The results could be described by:

parallel: D (cm2/s) = 3.0 x 10-1 exp[-0.46(eV)/kT]

perpendicular: D (cm2/s) = 3.0 x 10-1 exp[-0.76(eV)/kT]

B.Bayat, H.W.Wassmuth: Surface Science, 1983, 133[1], 1-8