Scanning tunnelling microscopy permitted the creation of large patches, on a (111)-(7 x 7) substrate, which exhibited 2 x 1 reconstruction. This could be done via a sudden increase in the sample bias, which produced large modifications of an initially flat area. Inspection of these strongly modified areas revealed a row of maxima that coincided with reported topographic and spectroscopic descriptions of the (111)-(2 x 1) surface. A mechanism was proposed in which extensive removal of material created a contact between the tip and the sample. The breaking of this contact, if crystalline, then exposed a bulk termination that reconstructed with the 2 x 1 pattern, as happened upon cleaving single crystals in the (111) orientation.

Local cleavage of the Si(111)-(7 x 7) surface J.I.Pascual, C.Rogero, J.Gómez-Herrero, A.M.Baró: Physical Review B, 1999, 59[15], 9768-70