Scanning tunneling microscopy imaging of facet surfaces of self-organized nanocrystal using metal-coated carbon nanotube tip

The facet surfaces of a self-organized ErSi2 nanocrystal were observed by the STM with a metal-coated carbon nanotube tip. The 10-nm-scale radius and high aspect ratio of the tip was able to provide detailed images of the facet surfaces. The stereographic STM imaging showed that the nanocrystal had (1 0 5) facets of the tetragonal ErSi2 on all facet surfaces with a 1 × 1 periodicity. Bias-dependent STM images revealed that the facet surface has a bulk-truncated structure consisting of Si dimers and Er atoms. Moreover, scanning tunneling spectroscopy exhibited a difference in density of states between top and facet surfaces.