The surface reconstruction of  in situ  prepared S-terminated and S-protected (001) samples was studied, using scanning tunnelling microscopy, at temperatures of up to 260C. A new re-ordering process from the (4 x 6) Ga-stabilized surface to the (2 x 6) S-stabilized surface was demonstrated, as well as a novel method of air protection by using a S passivation layer. Also,  in situ  observations were made of the annealing of this S-protection layer by means of high-temperature scanning tunnelling microscopy; thus avoiding adsorption from the environment, and verifying that the (2 x 6) structure still became dominant on the S-terminated (001) surface without the effects of As atoms.

S.Tsukamoto, N.Koguchi: Journal of Crystal Growth, 1995, 150[1-4], 33-7