The Study Of Nanometer Effect Induced By Ar^q+ Ions Impact On HOPG Surface

Recently, the highly charged ions sources, surface probing technique, ultra high vacuum and other experiment settings have developed very quickly. That can provide good conditions for the interactions of highly charged ions with solid. When the highly charged ions approach to the solid surface, it will not only induce the emission of different secondary particles, such as electrons, atoms, ions, but also strongly modify the solid surface in nano-scale. The interactions of slow highly charged ions with solid just modify the solid surface structure, won't destroy structures in solid. We can make a special nano-dot by changing ions charge state and kinetic energy.In this paper, we have observed nano-dots when highly charged argon ions impact on Highly Oriented Pyrolytic Graphite. By stating the nano-dots, we can acquire average values of nano-dots size and height for each type of ions. We want to study the contributions of kinetic energy and potential energy to nano-dots formation, and try to clarify the mechanism of the creation of nano-dots.It is found that nano-dots have been created only by kinetic energy when singly charged argon ions impact on Highly Oriented Pyrolytic Graphite, and both kinetic energy and potential energy have contributions to nano-dots creations when highly charged argon ions impact on sample. The potential energy effects will become stronger with increasing charge state of ions, it will restrain the kinetic energy effects. So the potential energy will become dominant for nano-dots formation when very highly charged ions interact with solid. To make simply, the kinetic energy have induced nano-dots because atoms strike each other to form defects or displacement of crystal lattice. While the nano-dots induced by potential energy can be explained by "Thermal Spike" model.