Atom resolved discrimination of chemically different elements on metal surfaces

Abstract
By reversibly manipulating the apex of the tip in a scanning tunneling microscope (STM), we can image either the O or the Cu or Ni atoms in the added rows which consistute the oxygen-induced (2×1) reconstruction of the (110) surfaces of Cu and Ni. This implies that the STM can be used to discriminate between chemically different elements on metal surfaces.