Scanning tunnelling microscopic studies were made of the (100) surface. Regions which were 150nm x 150nm in extent, with atomically flat areas fragmented by atomic steps, were observed. A reconstructed (100) surface, deformed to a twisted hexagon with an interatomic distance of 0.27nm, could be seen and a corrugation depth of about 0.05nm was measured. These results were in good agreement with reflection electron microscopic measurements and with scanning tunnelling microscopic data which had been obtained under ultra-high vacuum conditions.

T.Schilling, B.Tesche, G.Lehmpfuhl: Zeitschrift für Naturforschung, 1992, 47a[12], 1187-90