LOW-TEMPERATURE MANIPULATION OF AG ATOMS AND CLUSTERS ON A AG(110) SURFACE

We report on manipulation experiments performed with a scanning tunnel ing microscope (STM) on Ag(110) at T = 50 K. At high tunneling current s (I = 50 nA) the tip can move individual atoms and small clusters pre ferentially through troughs between densely packed atomic rows. At low er tunneling currents cross-channel motion along the diagonal of the s urface unit cell occurs which may indicate adatom-surface atom exchang e processes during the tip-induced motion. The interaction between the tip and the Ag adatom is shown to be attractive or repulsive dependin g on the polarity of the bias voltage. The transfer of Ag adatoms to t he tip and the subsequent redeposition are characterized in terms of c urrent versus distance measurements.