New Mechanism for Single Atom Manipulation

Abstract

Scanning tunneling microscope (STM) investigations of the step roughening of Ag(110) have shown that the STM tip extracts atoms from otherwise stable steps even at typical imaging conditions. Detailed analyses of single STM scans reveal that none of the so far known lateral manipulation mechanisms (pushing, pulling, sliding) account for the observed atom extraction. The Ag atoms rather follow the energetically favorable path of a tip induced exchange process, similar to the concerted motion proposed previously for the diffusion on fcc(110) surfaces including a metastable and thus experimentally detectable dumbbell transition state.

Fast scanning tunnelling microscopy as a tool to understand changes on metal surfaces: from nanostructures to single atoms

“…For example, it was shown that on Ag(110) at room temperature the tip extracts atoms by one lattice distance out of otherwise straight steps even within the GΩ range [19], however with a high scanning density [17]. Another example is shown in Fig.…”

“…Finally, the tip might influence the structural changes, in particular, if processes with low activation energy are studied [17]. The fact that the STM is utilized under rather similar experimental conditions as a microscope to image nanostructures and as a tool to create nanostructures underlines this challenge.…”

CO Oxidation as a Prototypical Reaction for Heterogeneous Processes

“…We note in passing that, indeed, the stoichiometry of a given cluster may be established by using tip manipulation techniques. [121,115,116] To understand the electronic structure we inspected the scanning tunneling spectra, as shown in Figure 11 c. The maxima correspond to the electron distribution within cluster states represented by the conduction images shown above the spectra. One may recognize the position of the nodal planes in the spatial electron distributions.…”

Controlled manipulation of single atoms and small molecules using the scanning tunnelling microscope

“…The manipulation of “native” substrate atoms on Cu(211) to positions close to foreign ad‐species could be used to determine adsorption sites of the latter due to the known ad‐sites of the metal atoms . Manipulation of Ag atoms perpendicular to the step edges on Ag(110) can also lead to particle exchange at the steps . Figure shows the formation of an artificial metallic structure: by lateral manipulation 36 Ag atoms have been positioned in a circle with diameter of 31.2 nm on a Ag(111) surface .…”