Phthalocyanine adsorption on Au(1 1 0): 1D ordering and adaptive reconstruction.

The adsorption of metal-free phthalocyanine molecules on an anisotropic Au(1 1 0)(1 × 2) surface has been studied with ultraviolet (UV) photoemission, low-energy electron diffraction and low-temperature scanning tunneling microscopy. In all cases, the molecules form rows in the [1 [Formula: see text] 0] direction, i.e. along the troughs of the reconstructed substrates. However, depending on the exposure and adsorption temperature, the substrate maintains (1 × 2)- or transforms into a (1 × 3)-reconstruction, and the molecular separation along the rows shrink from six to five times the Au-Au interatomic distance. The results are in agreement with previous density functional theory (DFT) calculations.

Distribution of Pd clusters on ultrathin, epitaxial TiO x films on Pt3Ti(111).

Scanning tunnelling microscopy (STM) was used to investigate the nucleation and growth of palladium clusters on two different, ultrathin, epitaxial, titania films grown on a Pt3Ti(111) surface. The first oxide phase, z'-TiO x , is anisotropic and consists of parallel stripes separated by trenches. Defects (i.e., oxygen vacancies) in this structure are confined to these trenches and act as nucleation sites. Therefore, the Pd clusters are mostly arranged in unidirectional rows along the trenches, creating a template effect. The second phase, w'-TiO x , exhibits a hexagonal, long range, (7 × 7)R21.8°, Moiré-type superstructure with fewer and shallower defects, making the template effect less discernible.