Noncontact Atomic Force Microscopy. Possibility of NC-AFM Imaging of Surface Magnetic Structure.

Abstract

Many kinds of scanning probe microscopes have been proposed for imaging surface magnetic structures. Theoretical calculations predict that the detection of the short-range magnetic interaction such as exchange interaction reveals the magnetic structures on an atomic scale. The non-contact atomic force microscopy (NC-AFM) detecting the short-range magnetic interaction is called exchange force microscopy (EFM). In order to detect the exchange interaction between a magnetic tip and a sample, we performed NC-AFM imaging of an antiferromagnet NiO(001) surface using a ferromagnetic Fe-coated tip. To discuss the interaction atomically resolved images obtained are analyzed by the superposition method. The results of the analysis demonstrates that the spin configuration revealed from the superimposed images coincides with the expected one of the NiO(001) surface. To evaluate the corrugation amplitude of the atoms, we introduced the topographic asymmetry, which indicates that the short-range magnetic interaction between the Fe-coated tip and sample can be detected by NC-AFM.