Scanning tunnelling microscopy was used to study the structure and electronic properties of the 5 x 5 reconstruction of the (111) surface. The 5 x 5 structure was formed by

annealing 2 x 1 cleaved surfaces. It was found that the structure of the 5 x 5 surface was consistent with the dimer - adatom - stacking-fault model. By comparing neighboring regions of 2 x 1 and 5 x 5 structures, a p-bonded chain structure for the 2 x 1 surface was confirmed.

R.M.Feenstra, M.A.Lutz: Journal of Vacuum Science and Technology B, 1991, 9[2], 716-20