Atomic diffusion of Au on the (111) surface, induced by a voltage pulse, was demonstrated by using a scanning tunneling microscope, with an Au tip, in air. By applying a voltage pulse as a trigger, local diffusion of Au atoms around the position where the voltage pulse was applied could be observed. Upon repeating tip scanning, finger-like stripes grew gradually from a step. The direction of the stripes was affected by the structure of the Au(111) surface and the tip-scan direction. In the present experiments, movable Au atoms on the local area were swept by tip scanning via the field gradient effect. Local atomic Au diffusion could be induced since the activation energy was reduced by applying the voltage pulse.

Local Atomic Diffusion on Au(111) Surface Induced by Au Tip. J.Kim, H.Uchida, K.Yoshida, H.Kim, K.Nishimura, M.Inoue: Japanese Journal of Applied Physics - 1, 2003, 42[6A], 3616-8