Scanning tunneling microscopy images of the atoms in the corner holes on the Si(111)-(7×7) surface with bismuth-covered tips

The use of special tips in scanning tunneling microscopy experiments for studying the Si(111)-(7×7) surface is considered. The special tips are created by bismuth deposition on tungsten tips. Images of the atoms in the corner holes are obtained for the first time and the unartificial nature of the images has been checked by the adsorption of a low amount of atomic hydrogen on the Si(111)-(7×7) surface.