Realistic model tips in simulations of nc-AFM

In this study we use first principle methods to study the interaction of three different tip models with a CaF(2) (111) surface. The tip models are based on a 'realistic' approach to tip simulation and consist of a pure silicon tip, an oxygen terminated silicon tip and a water contaminated silica (SiO(2)) tip. We find that each tip demonstrates characteristic features which should be observable in experiments and hence provide signatures which would aid in the identification of tip and surface species.