Atomic resolution on a metal single crystal with dynamic force microscopy

Atomically resolved frequency modulation dynamic force microscope (FM-DFM) images taken by a tuning fork setup on an Ag(001) surface are presented. The necessity of well chosen tip surface interaction parameters is demonstrated making atomically resolved FM-DFM images on metal surfaces scarce. The capability of our setup to measure frequency shift and simultaneously tunneling current gives insight into different tip trajectories and possible contrast formation mechanisms in FM-DFM and scanning tunneling microscopy. One explanation is related to local variations in the decaying signals, which may originate from different density of states contributions to tip-sample force and tunneling current.