Simulating dynamic force microscopy imaging of a NaCl island using non-idealtips

Abstract

We use atomistic simulation to study how the contrast pattern in dynamic force microscopydepends on the structure of the tip. Using a NaCl island on the NaCl(001) surfaceas a template, we consider several different NaCl tip configurations, with andwithout OH contamination. We find that the most significant changes in images areproduced by very soft tips, which demonstrate large relaxations due to tip–surfaceinteraction. Harder tips produce qualitatively similar images regardless of the atomicconfiguration presented to the surface. Contamination of the tip by hydroxylgroups reduces the strength of the interaction, and, in certain configurations,can produce asymmetries in the image even on the flat terrace of the island.