Effect of lateral tip stiffness on atomic-resolution force field spectroscopy

Atomic force microscopy is being increasingly used to measure atomic-resolution force fields on sample surfaces, making correct interpretation of resulting data critically important. In addition to asymmetry, elastic deformations undergone by the microscope tip are thought to affect measurements. In this study, simple analytical potentials and a model tip apex were used to theoretically analyze how lateral tip stiffness affects force spectroscopy on the surface of NaCl(001). The results suggest that lateral deformations experienced by the tip lead to certain distortions in measured force spectra, the degree of which depends on lateral tip stiffness.