SCANNING PROBE MICROSCOPY STUDY OF LAYERED DICHALCOGENIDE RES2

The surface of the layered chalcogenide ReS2 was examined by atomic fo rce microscopy (AFM) and scanning tunneling microscopy (STM), and the structure of ReS2 was determined by single crystal X-ray diffraction m easurements. The observed atomic-resolution AFM and STM images were an alyzed by calculating the total and partial electron density distribut ions [p(r(0)) and p(r(0),rho(f)), respectively] of a single ReS2 layer taken from the bulk crystal structure. Our results show that the STM images are associated with the surface S atoms. The p(r(0),rho(f)) plo ts of the two tunneling processes differ in topography from the p(r(0) ) plot so that the surface atomic structure cannot be unambiguously de duced from the analysis of atomic-resolution STM images alone. Calcula tions of the p(r(0)) and p(r(0),rho(f)) plots are essential for proper ly interpreting the atomic-resolution AFM and STM images.