Measurements of surface self-diffusion by the field emission fluctuation method along the zones (011)-(112) and (011)-(001) of a tungsten emitter show both 2 and I dimensional diffusion, attributed to diffusion of W atoms on the terraces and of kinks along the edges of the stepped surfaces found in these zones. At 950 K -1000 K the steps along (011)-(112) disorder completely, as indicated by the merging of the two types of diffusion into a single, 2-dimensional regime. Along (011)-(001) definite transitions can only be seen on (023) and (017). The transition temperatures are much lower, ~750 K.
Gomer, R. and Gong, Y. M.
"Surface Roughening Studies by Field Emission,"
Scanning Microscopy: Vol. 1
, Article 9.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss4/9