Herringbone reconstruction

By taking STM images of a smaller area, it was found that the spontaneous formation of ordered arrays of Ni islands is determined by the herringbone reconstruction of the Au(lll) surface. It is clear that the Ni islands locate at the elbows of the herringbone structure. A detailed study of the atomic-resolution STM image and the local atomic structure near the elbows indicates that at each vertex of the elbow, there is a dislocation. Energetically, the dislocation site is the most probable location for the nickel deposition to nucleate. 

Fig. 11. STM images 4035Ax4090A of molybdenum deposited on the Au(l 11) surface at room temperature and under UHV conditions. The inset (890Ax920A) shows the location in the bulged elbows of the herringbone reconstruction of 20-A wide molybdenum nanoclusters.

Of course, the classic example of the role of the tensile surface stress of a clean surface acting as the driving force for reconstruction to a surface of higher atomic density is the so-called herringbone reconstruction of Au(lll) mentioned earlier, in which extra rows of Au are added in the surface layer [61]. The addition of A1 to this surface leads to a different reconstruction ( distorted hexagonal ) with an density that is enhanced by 10% with respect to a bulk (111) layer [68]. The reconstruction is similar to the one found on Au(lll) at elevated temperatures, in which case the density enhancement amounts to 7%. Bearing in mind that the atomic radius of A1 is almost identical to that of Au (less than 1% smaller), the A1 atoms evidently display a reduced effective radius in this surface alloy, as manifest in reduced rumpling amplitudes in the many systems we have discussed in this chapter. 

Comparative studies in an electrochemical environment and under UHV conditions gain detailed information on die mechanistic role on anions and solvent molecules. This is demonstrated for nucleation and growth of thin epitaxial Ni films on Au(l 11). In contrast to Cu, no UPD or anion effects were found for Ni on Au [25]. In addition, due to the negative deposition potential of Ni the Au(l 11) electrode can be kept in a potential regime in vdiich Ihe surface exhibits the herringbone reconstruction, well known fiom UHV studies [26]. In Fig. 4(a), recorded in a modified Watts electrolyte [25], the zigzag pattern of die herringbone reconstruction is clearly visible on the electrode surface. 

A reconstruction, which is similar in size to the above-mentioned herringbone reconstruction of the Au(l 11) surface is the Pt(100)-(5 x20) (or Pt(lOO)-hex) and Pt(100)-hex-R0.7° reconstruction (Fig. 8) [26-31]. Similar reconstructions are present on the Ir(lOO) [26,28,32] and Au(lOO) surface [28,33]. These systems share the peculiarity that the topmost layer is quasi-hexagonally reconstructed, which leads to an atom density that is about 20% higher than in the underlying lOO planes and about 8% higher than... 

One can obtain a stable catalyst for the WGS by adding CeO nanoparticles to Au(lll)." On an inverse oxide/metal catalyst, the reactants can interact with defect sites of the oxide nanoparticles, metal sites, and the metal/oxide interface. Figure 6.10 shows a STM image obtained after depositing ceria nanoparticles on Au (111). There is a random distribution of the ceria nanoparticles on the terraces of the gold substrate which maintains its characteristic herringbone reconstruction. The particles occupy specific sites with respect to the dislocation ridges of the reconstruction. The initial oxidation state of the Ge cations in the ceria nanoparticles was +4 and many of them were reduced to Ce upon exposure to the reactants of the WGS. ... 

At these potentials, nucleation proceeded exclusively at the elbow sites of the Au(lll) herringbone reconstruction, leading to a self-organized surface patterning of nanoscale Cd islands. 

Narasimhan, S. Vanderbilt, D. 1992. Elastic stress domains and the herringbone reconstruction on... 

Atkin R, Borisenko N, Druschler M, el-Abedin SZ, Endres F, Hayes R, Huber B, RoUng B (2011) An in situ STM/AFM and impedance spectroscopy study of the extremely pure l-butyl-l-methylpyrroUdinium tris(pentafluoroethyl)trifluorophosphate/Au(lll) interface potential dependent solvation layers and the herringbone reconstruction. Phys Chem Chem Phys 13(15) 6849-6857. doi 10.1039/c0cp02846k... 

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