Scanning tunnelling microscope tip-induced diffusion of In atoms was observed on the (111) v3 x v3-In surface. It was found that In migration to the region beneath the tunnelling tip resulted in an increase in In coverage and a spontaneous, v3 x v3-In → 2 x 2-In, structural transformation at negative tip-bias voltages. At a positive tip bias voltage, In diffusion from the region beneath the tunnelling tip resulted in a decrease in the In coverage and a v3 x v3-In → 2 x 2-In structural transformation. The In adatoms showed up as being positively charged. Scanning tunnelling microscope tip field-induced In migration occurred at room temperature, at bias voltages which were typical for scanning tunnelling microscopic observations; without requiring additional tip movement towards the surface.

A.A.Saranin, T.Numata, O.Kubo, H.Tani, M.Katayama, V.G.Lifshits, K.Oura: Physical Review B, 1997, 56[12], 7449-54