STM image constant-current

Figure 4.7b shows a close-up of Figure 4.7a, a 300 pA constant It contour, which has a corrugation of approximately 100 pm and is located approximately 300 pm from the 02c surface atoms. These values disagree quantitatively with experimental STM results at the same tunneling conditions on two accounts. First, a set point of It= 300 pA is not a particularly large value for constant current STM imaging, and... 

Figure 4.18. Constant-current STM images (70 nm x 70 nm) acquired at 50 K of long-range ordered MLs of M-heptahelicene on Cu(l 11). (a) 6 3-structure at = 0.95 ML and (b) 3-structure of = 1 ML. 1 ML is defined as the saturation coverage. The insets show the molecular cluster units of the structures. Reprinted with permission from Fasel et al, 2003.

FIGURE 3.2. (a) Chemical structure of octanethiol. (b) A constant current STM image of octanethiol SAM on Au(l 11). Au reconstruction is lifted and alkanethiols adopt commensurate crystalline lattice characteriized by a c(4 x 2) superlattice of a (a/3 x V3)R30°. (c) Model of commensuration condition between alkanethiol monolayer (large circles) and bulk-terminated Au surface (small circles). Diagonal slash in large circles represents azimuthal orientation of plane defined by all-trans hydrocarbon chain. (Reprint with permission from Ref.25 G. E. Poirier, Chem. Rev., 97, 1117-1127 (1997). Copyright 1997 American Chemical Society.)... 

Fig. 35. Four constant current STM images of the (001) surface of Na doped V2O5 recorded with similar experimental parameters (U 2-3 V, I 0.6-1.0 nA) [167]. Images (a), (b), and (c) have the same scale and orientation. The image in (d) covers a slightly larger area and has a different orientation. The surface repeat unit is indicated by the rectangle in (a). The vertical scale from black to white is in (a) 2.25 A, (b) 1.5 A, (c) 1 A and (d) 2.25 A.

Figure 24 Constant-current STM image of a Cu(lll) surface measured at 4K (Vt = 0.1 V and It = 1.0 nA). Spatial oscillations with a periodicity of 15 A are clearly emanating from monatomic step edges and point defects. (From Ref. 53.)...

Figure 15 (a) A constant-current STM image of a 0.25 MLE Au deposited onto Ti02(l 10)-... 

Fig. 18 A simulated, constant-current STM image of a hypothetical X3 molecule in its high-symmetry D31, configuration is shown in (a). The (x, y)-axes are arranged so that atom a lies on the y-axis and the centre of mass is at the origin. The corresponding degenerate normal modes of vibration are shown in (b) and (c)...

Fig. 10.36. STM image and schematic view of a SiNW with Si (111) facet, (a) Constant current STM image of a SiNW on a HOPG substrate. The wire s axis is along the [112] direction, and (b) schematic view of SiHs on Si (111) viewed along the [111] direction. Red and...

Fig. 8 Constant-current STM images of Au-boimd Mni2 clusters containing the ligands L (a) and mtb (b). The insets show three isolated molecules (a) and a 3-D representation of a 200 X 200 nm area with gold terraces and a triangular feature typical of Au( 111) reconstruction (b) (adapted from [89] and [90])...

Fig. 4. Constant current STM image of an atomically clean Cu(100) surface after exposure to a full monolayer coverage of HBDC molecules (Fig. 1). Each molecule appears as a hexagonal six-lobed structure. Reprinted with permission from [9]. Copyright 1998 American Association for the Advancement of Science...

Fig. 6. Constant-current STM image of an atomically clean Cu(100) surface after exposure to a monolayer coverage of HBDC molecules just before the threshold of full coverage. Holes in the monolayers are readily observed, in which some HBDC molecules have been observed to rotate freely for some time. Note that the HBDC molecules at the border of these holes generally are not moving owing to their interaction with the surrounding ordered part of the corresponding monolayer island. In A the central molecule is fixed and in B after a translation of 0.25 nm the central molecule is observed to rotate. Reprinted with permission from [9], Copyright 1998 American Association for the Advancement of Science...

Fig. 3.17 Constant current STM image of an alloy of approximately 0.3 MF Gd and 0.4 MF Fe. The striped areas represent the well-known Gd superstructures with the stripes being aligned along the [001] direction of the substrate. The smooth areas correspond to an alloy of GdFc2. The scan range is 70 nm X 70 nm. Sample bias U = 0.2 V, tunneling current / = 0.3 nA. Reprinted with permission from [38]. Copyright (1999) by the American Physical Society...

Figure 2. A) Voltammetric desorption of bromide from an irreversibly adsorbed Pt(lll)-Br layer, in O.IM H2SO4. Arrows indicate the evolution of the voltammetric profile. Sweep rate 50 mV s . B) Constant current STM image of the close-packed bromine adlayer on Pt(l 11).

Fig.13 a Molecular structure of 26. b, d Constant-current STM images (10.5 x 6.9 nm ) on Cu(llO) under UHV conditions, b 26 double-row structure. The trenches in the underlying surface are sketched, c Ball model of the double-row structure. The substrate atoms are shaded darker the deeper the layers lie. The molecules are shown in gray. d The trenches in the surface layers are disclosed after manipulating the molecules aside. (Reproduced with permission from Ref. [70])... 

Few defects are present. Insets show constant current STM images at (b) negative bias and filled states and (c) positive bias and empty states. 

Figure 9.26 Constant current STM image of the Si(lll)-(7x7) structure. Empty states are imaged (Ubias = 2.0 V). Atomic steps are present in the large scan. The inset shows a magnification of the unit cell. The two subunits of the (7x7) are not identical.

Figure 7.9 (a,b) Constant-current STM images of a single porphycene molecule adsorbed on Cu(110) (size 1.49x 1.42 nm, gap conditions /, = 10 nA and K = 100 mV). The gray scale represents the apparent (topographic) height of the STM (i.e., the vertical displacement of the STM tip), and the zero point corresponds to the surface level. The white grid lines correspond to the surface lattice of Cu(110) underneath the molecule (the lattice constants are... 

Figure 4. Constant current STM image of the surface of a 1 mm diameter mercury sessile drop with no thiol coating. The bias voltage is 270 mV and scan frequency is 78 Hz. The scanning range is 20 by 20 nm with the fast scanning x-direction shown on the right axis, and the slow scanning y-direction shown on the left axis.

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