Scanning tunnelling microscopy was used to study the reconstructions of Si-terminated (00•1) surfaces which were observed after heat treatment at increasing temperatures. In the case of the 3 x 3 reconstruction, obtained by heating at temperatures of about 950C, the images could be explained in terms of a model that involved 1/3 of a monolayer of Si or C adatoms in 3-fold symmetrical sites on top of the outermost Si-C bilayer. In the case of surfaces which had been heated to temperatures above 1050C, the images exhibited increasing fractions of quasi-periodic 6 x 6 and 5 x 5 reconstruction. Heating to temperatures above 1250C resulted in partial graphitization of the surface, and modified the observed 6 x 6 structure.

F.Owman, P.Mårtensson: Journal of Vacuum Science and Technology B, 1996, 14[2], 933-7