The scanning tunnelling microscope

The STM is still widely used today, in particular for the analysis of conducting or semi-conducting substrates. The resultant STM images are most often related to sample topography, but it should be noted that the technique in fact directly measures the localized charge densities of a surface. Although the STM has also been successfully employed for biomolecular imaging in a small handful of studies, the requirement for the sample to be conductive has meant that its use in this area is somewhat limited. 

---

Fig. VIII-1. Schematic illustration of the scanning tunneling microscope (STM) and atomic force microscope (AFM). (From Ref. 9.)...

Marrian C R K, Perkins F K, Brandow S L, Koloski T S, Dobisz E A and Calvert J M 1994 Low voltage electron beam lithography in self-assembled ultrathin films with the scanning tunneling microscope Appi. Rhys. Lett. 64 390... 

Stroscio J A and Eigler D M 1991 Atomic and molecular manipulation with the scanning tunneling microscope Science 254 319... 

Hamers R, Avouris P and Boszo F 1987 Imaging of chemical-bond formation with the scanning tunnelling microscope NH, dissociation on Si(OOI) Rhys. Rev. Lett. 59 2071... 

Tang S L, McGhie A J and Suna A 1993 Molecular-resolution imaging of insulating macromolecules with the scanning tunnelling microscope via a nontunnelling, electric-field-induced mechanism Phys. Rev. B 47 3850... 

Maaloum M, Chretien D, Karsenti E and FIdrber J K FI 1994 Approaching microtubule structure with the scanning tunnelling microscope (STM) J. Ceii Sc/. 107 part II 3127... 

Fig. 4. Atom manipulation by the scanning tunneling microscope (STM). Once the STM tip has located the adsorbate atom, the tip is lowered such that the attractive interaction between the tip and the adsorbate is sufficient to keep the adsorbate "tethered" to the tip. The tip is then moved to the desired location on the surface and withdrawn, leaving the adsorbate atom bound to the surface at a new location. The figure schematically depicts the use of this process in the formation of a "quantum corral" of 48 Fe atoms arranged in a circle of about 14.3 nm diameter on a Cu(lll) surface at 4 K.

This slow diffusion of a crucial new technique can be compared with the invention of the scanning tunnelling microscope (STM) by Binnig and Rohrer, first made public in 1983, like X-ray diffraction rewarded with the Nobel Prize 3 years later, but unlike X-ray diffraction quickly adopted throughout the world. That invention, of comparable importance to the discoveries of 1912,now(2 decades later) has sprouted numerous variants and has virtually created a new branch of surface science. With it, investigators can not only see individual surface atoms but they can also manipulate atoms singly (Eigler and Schweitzer 1990). This rapid adoption of... 

The bundle of MWCNT can be released in ultrasonic cleaner using ethanol as the solvent. The scanning tunnelling microscope (STM) image of thus released MWCNT is shown in Fig. 2. 

G- Binning and H. Rohrer (Zurich) design of the scanning tunneling microscope. 

The main technique employed for in situ electrochemical studies on the nanometer scale is the Scanning Tunneling Microscope (STM), invented in 1982 by Binnig and Rohrer [62] and combined a little later with a potentiostat to allow electrochemical experiments [63]. The principle of its operation is remarkably simple, a typical simplified circuit being shown in Figure 6.2-2. 

Three scanning probe techniques are described in more detail below the scanning tunneling microscope, the atomic force microscope, and the friction force microscope. 

The scanning tunneling microscope (STM) was invented by Binnig and Rohrer in 1982. This quickly led to the award of a Nobel prize in 1986. Initially, STM proved... 

The basis of the scanning tunnelling microscope, illustrated schematically in Figure 3.5, lies in the ability of electronic wavefunctions to penetrate a potential barrier which classically would be forbidden. Instead of ending abruptly at a... 

Hamers RJ (1989) Atomic-resolution surface spectroscopy with the scanning tunneling microscope. Ann Rev Phys Chem 40 531-559... 

Tersoff J, Hamann DR (1983) Theory and application for the scanning tunneling microscope. Phys Rev Lett 50 1998... 

Eigler D, Lutz CP, Rudge WE (1991) An atomic switch realized with the scanning tunneling microscope. Nature 352 600... 

The scanning tunneling microscope (STM) is an excellent device to obtain topographic images of an electrode surface [1], The principal part of this apparatus is a metal tip with a very fine point (see Fig. 15.1), which can be moved in all three directions of space with the aid of piezoelectric crystals. All but the very end of the tip is insulated from the solution in order to avoid tip currents due to unwanted electrochemical reactions. The tip is brought very close, up to a few Angstroms, to the electrode surface. When a potential bias AF, usually of the order... 

---