Tunneling microscope, schematic

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

Figure C3.2.3. Schematic view of a scanning tunnelling microscope. From Chen C J 1993 Introduction to Scanning Tunnelling Microscopy (Oxford Oxford University Press).

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 The tip is then moved to the desired location on the surface and withdrawn, leaving the adsorbate atom bound to the surface at a new location.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.

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... 

The scanning tunneling microscope uses an atomically sharp probe tip to map contours of the local density of electronic states on the surface. This is accomplished by monitoring quantum transmission of electrons between the tip and substrate while piezoelectric devices raster the tip relative to the substrate, as shown schematically in Fig. 1 [38]. The remarkable vertical resolution of the device arises from the exponential dependence of the electron tunneling process on the tip-substrate separation, d. In the simplest approximation, the tunneling current, 1, can be simply written in terms of the local density of states (LDOS), ps(z,E), at the Fermi level (E = Ep) of the sample, where V is the bias voltage between the tip and substrate... 

See Surface Brillouin zone Scanning tunneling microscope 1 concentric-tube 111 low-temperature 275 pocket-size 270 schematic diagram 1 single-tube 273... 

Figure 8.17 Left Schematic of a scanning tunneling microscope (STM). Right STM image (2.7 x 2.7 nm) of the atomic structure of a copper (111) surface imaged in an aqueous medium after electrochemical cleaning [357]. The image was kindly provided by P. Broekmann and K. Wandelt.

The Scanning Tunneling Microscope. An STM uses a sharp metallic tip as a probe for the measurement. The tunneling tip is typically a wire that has been sharpened by chemical etching or mechanical grinding. W, Pt/Ir, or pure Ir are often used as the tip material. A schematic view of an STM is shown in Fig. 2. 

Figure 6.32 Schematic diagram depicting the mechanism of electrochemical metal deposition on graphite surfaces in the scanning tunneling microscope [6.193). Reprinted by permission of Kluwer Academic Publishers.

Figure 22 (a) Schematic diagram of a scanning tunneling microscope. An applied bias... 

Fig. 8.12. Nanoelectronic devices (a) Schematic diagram [163] for a carbon NT-FET. Vsd, source-drain voltage Vg, gate voltage. Reproduced from ref [163], with permission, (b) Scanning tunneling microscope (STM) picture of a SWNT field-effect transistor made using the design of (a) the aluminum strip is overcoated with aluminum oxide, (c) Image and overlaying schematic representation for the effect of electrical pulses in removing...

Instrumental application of surface-plasmon-enhanced fluorescence was applied in using a TP scanning tunneling microscope [363], This was employed to probe the TP excited fluorescence from organic nanoparticles adsorbed on a silver surface. A size dependence of fluorescence enhancement and photodecomposition was reported as a result of competition between surface-plasmon-enhanced TP fluorescence and nonradiative energy transfer from the excited dye molecules to the silver surface. The schematic experimental setup is shown in Figure 3.14 [363]. 

Figure 3.14. Schematic setup for a TP tunneling microscope for probing surface-plasmon-induced local field enhancement of TP excited fluorescence for organic nanoparticles coated on a silver surface. (From Ref. [363] with permission of the American Chemical Society.)...

Figure 13.5.2 a) Schematic representation of an adsorbed layer with a (V3 X V3)R30° Structure on a gold (111) surface, b) Scanning tunneling microscope image of a 40 A X 40 A region of a 4-aminothiophenol monolayer on an Au (111) surface. Note difference in Spacing compared to that in Figure 13.5.1 [Part b reprinted with permission from Y.-T. Kim, R. L. McCarley, and A. J. Bard, J. Phys. Chem., 96, 7416 (1992). Copyright 1992, American Chemical Society.]...

FIGURE 339. Schematic of the scanning tunneling microscope (STM) the tip of which is of atomic dimension (P. Avouris, Accounts of Chemical Research, 28 95, 1995 courtesy American Chemical Society the author thanks Dr. Phaedon Avouris, IBM Research Division, for this figure). 

A) Schematic diagram of the scanning tunneling microscope (STM) in which a tip of atomic dimensions glides across an atomic surface but does not touch it. Electrons are exchanged between the surface and the probe tip by quantum mechanical tunneling. B) The quantum corral was made by moving 48 iron atoms into a circle. 

Figure 3 Schematic of Oj molecules and O atoms (gray) adsorbed on a platinum surface (left). The image generated by the scanning tunneling microscope reveals two shapes of oxygen molecules on the platinum surface (right). Molecules can...

Schematics of a high-piessuie scanning tunneling microscope integrated in a microflow reactor and a flow reactor for in situ SXRD. From Ref. [23], 2007, Cambridge University Press and Ref. [26], reproduced with permission, 2010, American Institute of Physics.

Figure 11.2. Schematic representation of the scanning tunneling microscope a metal tip is held at a voltage bias V relative to the surface, and is moved up or down to maintain constant current of tunneling electrons. This produces a topographical profile of the electronic density associated with the surface.

FIGURE1 (A) Schematic illustration of a scanning tunneling microscope. (B) Tip trajectory as it tracks surface atomic structure in constant-current mode. 

The Atomic Force Microscope. The principle setup of an AFM is comparable to that of an STM, except that the tunneling tip is replaced by a force sensor (cantilever). A schematic view of an AFM is shown in Fig. 4. A sharp, not necessarily conductive tip, is mounted on the end of a spring. 

Figure 3.1 Schematic illustrations of (a) the scanning tunneling and (b) the atomic force microscopes...

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