Mechanism of nanostructure formation with the scanning tunneling microscope

In scanning tunneling microscope experiments with high voltage pulses hillocks are formed on the substrate. The conjecture which explains these nanostructures in terms of field ion evaporation is discussed and rejected. Another model for the Au-Au system is proposed on the basis of local melting of the tip by the Nottingham effect. The resistive Joule heating is shown to be negligible.