MICROSCOPIC INTERACTION BETWEEN A GOLD TIP AND A PB(110) SURFACE

We have studied the interaction in the contact regime between a pyrami dal gold tip and a Pb(110) surface using molecular dynamics simulation . Runs have been done at room temperature and in the surface melting r egime of the substrate. We present results on the force acting on the tip as a function of distance, and on the formation of adhesion necks, their nature and their effect on the structural and diffusive propert ies of the substrate. The adhesion neck between the tip and a melted s urface has also a liquid-like nature, explaining recent STM observatio ns.