Atomistic modeling of imaging of ionic surfaces with a scanning force microscope

Abstract

We present a simple theoretical model of the scanning force microscopy experiment using an atomistic simulation technique. The scanning of the perfect (100) surfaces of NaCl and LiF, the Mg2+ impurity ion on the surface of LiF, and the monoatomic step edge on the surface of NaCl were modeled at different constant vertical forces exerted on the tip. The calculations were made using an atomistic treatment of the interaction between a crystalline sample and tip nanoasperity combined with a semiempirical treatment of the mesoscopic van der Waals attraction between tip and surface and the macroscopic parameter of cantilever deflection. Comparing these results with experimental data, we discuss the quality of our model and the different conditions of surface imaging with atomic resolution.