The adsorption of graphene on Ni(111) has been investigated the basis adiabatic-connection fluctuation-dissipation theorem in random phase approximation (RPA). Although we find a significant hybridization between $\ensuremath{\pi}$ orbitals and Ni ${d}_{{z}^{2}}$ states at binding distance 2.17 \AA{}, energy is still range typical physisorption (67 meV per carbon). An important contribution to related decrease exchange resulting from adsorption-induced lower symmetry layer. energetics can be...

The dissociative adsorption of oxygen on the (111) surfaces platinum, palladium, and nickel has been investigated using ab initio local-spin-density calculations. For all three surfaces, is shown to be precursor-mediated structural, energetic, vibrational electronic properties precursors are in very good agreement with available experimental information. investigation transition states shows that Pt Pd barriers for dissociation comparable (or at sufficiently high coverage even higher than)...

Muscovite mica, KAl$_2$(Si$_3$Al)O$_{10}$(OH)$_2$, is a common layered phyllosilicate with perfect cleavage planes. The atomically flat surfaces obtained through cleaving lend themselves to scanning probe techniques atomic resolution and are ideal model minerals clays. Despite the importance of cleaved mica surfaces, several questions remain unresolved. It established that K$^+$ ions decorate surface, but their intrinsic ordering -- unaffected by interaction environment not known. This work...

The adsorption of unsaturated hydrocarbons on metallic surfaces is fundamental and applied interest, in view its implications as a model system for catalysis the refining industry. In particular, relation between type hydrocarbon strength remains an open question. Thus, we propose comparative DFT study several relevant catalytically Pd(111) Pt(111) surfaces. key features (structural, electronic, energetic, spectroscopic) are analyzed consistent way two olefins (ethylene, 1-butene), one...

The thermodynamic equilibrium shape of rhodium and palladium crystals are predicted under conditions from ultrahigh vacuum to high oxygen pressures using the Gibbs-Wulff construction. analysis is based on data obtained ab initio calculations for adsorption low-index (111), (100), (110) surfaces, stepped (311), (211), (331) surfaces. While close-packed (111) facets dominate in low-coverage cases, higher energies at more open surfaces lead a rounding crystallite. A linear correlation between...

Realization of graphene moir\'e superstructures on the surface 4d and 5d transition metals offers templates with periodically modulated electron density, which is responsible for a number fascinating effects, including formation quantum dots site selective adsorption organic molecules or metal clusters graphene. Here, applying combination scanning probe microscopy/spectroscopy density functional theory calculations, we gain profound insight into electronic topographic contributions to...

Graphene has a close lattice match to the Ni(111) surface, resulting in preference for 1 × configurations. We have investigated graphene grown by chemical vapor deposition (CVD) on nickel carbide (Ni(2)C) reconstruction of with scanning tunneling microscopy (STM). The presence excess carbon, form Ni(2)C, prevents from adopting preferred configuration and leads grain rotation. STM measurements show that residual Ni(2)C domains are present under rotated graphene. Nickel vacancy islands...

Macroscopic properties of materials stem from fundamental atomic-scale details, yet for insulators, resolving surface structures remains a challenge. The basal (0001) plane ${\alpha}$-Al$_{2}$O$_{3}$ was imaged with noncontact atomic force microscopy an atomically-defined tip apex. forms complex $({\sqrt31} {\times} {\sqrt31})R{\pm}9{\deg}$ reconstruction. lateral positions the individual O and Al atoms come directly experiment; how these connect to underlying crystal bulk determined based...

Platinum-group metals and noble play an important role in catalysis, for total oxidation as well partial reactions. Only recent years have advances microscopic, spectroscopic computer simulation techniques made it possible to investigate the interaction of oxygen with metallic substrates at atomistic level. We present overview on formation adsorption structures surface oxides Rh, Pd, Ag, Cu Pt surfaces, particular focus phase diagrams calculated from first-principles thermodynamics. The...

The catalytic activity of palladium toward selective hydrogenation hydrocarbons depends on the partial pressure hydrogen. It has been suggested that reaction proceeds selectively only when a carbon-rich film is present at metal surface. On basis first-principles simulations, we show carbon can dissolve into because graphite formation delayed by large critical nucleus necessary for nucleation. A bulk carbide Pd(6)C with hexagonal six-layer fcc-like supercell forms. structure characterized...

The structural evolution of graphene on Ni(111) is investigated as a function growth temperature by scanning tunneling microscopy (STM). Low (400–500 °C) results in continuous but highly defective film with small ordered domains and disordered composed Stone–Wales (SW)-like defects. As the increased, shrink leaving clusters defects alongside epitaxially matched graphene. Density functional theory (DFT) calculations indicate crucial role metallic support for healing SW defects, interaction...

We report on the structural and electronic properties of an artificial graphene/Ni(111) system obtained by intercalation a monatomic layer Ni in graphene/Ir(111). Upon intercalation, grows epitaxially Ir(111), resulting lattice-mismatched graphene/Ni system. By performing scanning tunneling microscopy measurements density functional theory calculations, we show that intercalated leads to pronounced buckling graphene film. At same time, enhanced interaction is measured angle-resolved...

Using a combined experimental and theoretical approach, we show that the initial oxidation of Rh(553) surface, surface vicinal to (111), undergoes step bunching when exposed oxygen, forming lower-index facets. At pressure about ${10}^{\ensuremath{-}6}\phantom{\rule{0.3em}{0ex}}\mathrm{mbar}$ temperature $380\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ this leads (331) facets with one-dimensional oxide chains along steps, coexisting (111) Further increase results...

The oxidation of a vicinal Pd(553) surface has been studied from ultrahigh vacuum (UHV) to atmospheric oxygen pressures at elevated sample temperatures. investigation combines traditional electron based UHV techniques such as high resolution core level spectroscopy, low-energy diffraction, scanning tunneling microscopy with in situ x-ray and ab initio simulations. In this way, we show that the O atoms preferentially adsorb step edges below...

Ultrathin (∼3 Å) zirconium oxide films were grown on a single-crystalline Pt3Zr(0001) substrate by oxidation in 1 × 10–7 mbar of O2 at 673 K, followed annealing temperatures up to 1023 K. The ZrO2 are intended serve as model supports for reforming catalysts and fuel cell anodes. atomic electronic structure composition the determined synchrotron-based high-resolution X-ray photoelectron spectroscopy (HR-XPS) (including depth profiling), low-energy electron diffraction (LEED), scanning...

Despite its importance in many areas of industry, such as catalysis, fuel cell technology and microelectronics, the surface structure physical properties ZrO2 are not well understood. Following successful growth ultra-thin zirconia on Pt3Zr(0 0 1) (Antlanger et al 2012 Phys. Rev. B 86 035451), we report recent progress into thin films, which were prepared by oxidation a Pd3Zr(0 crystal. Results from scanning tunneling microscopy (STM), Auger electron spectroscopy (AES), x-ray photoelectron...

We report on the self-organized growth of monatomic transition-metal oxide chains ($3\ifmmode\times\else\texttimes\fi{}1$) periodicity and unusual $M{\mathrm{O}}_{2}$ stoichiometry ($M=\mathrm{Ni}$, Co, Fe, Mn) Ir(100). analyze their structural magnetic properties by means quantitative LEED, STM, density functional theory (DFT) calculations. LEED analyses reveal a fascinating common atomic structure in which atoms sit above missing-row surface are coupled to substrate only via oxygen atoms....

The initial oxidation of the Rh(110) surface was studied by scanning tunneling microscopy, core level spectroscopy, and density functional theory. experiments were carried out exposing to molecular or atomic oxygen at temperatures in 500-700 K range. In ambient, terminates coverage close a monolayer with formation alternating islands (10x2) one-dimensional oxide (2x1)p2mg adsorption phases. use facilitates further until structure c(2x4) periodicity develops. experimental theoretical results...

The catalytic oxidation activity of palladium is influenced by the state metal. Under technologically relevant conditions, bulk and surface oxides may form decompose. By employing first-principles calculations based on density functional theory, we have investigated transition from oxide to Pd(100). We show that most stable orientation film PdO(101)@Pd(100) at any thickness. monolayer has unique electronic, chemical, thermodynamic properties in comparison thicker films. In particular, carbon...

Using scanning tunneling microscopy and density functional theory, we have studied the initial oxidation of Rh(111) surfaces with two types straight steps, having ${100}$ ${111}$ microfacets. The one-dimensional (1D) oxide initially formed at steps acts as a barrier impeding formation 2D on (111) terrace behind it. We demonstrate that details structure 1D govern rate discuss implications for nanoparticles.

We have studied the surface of pure and oxidized Pt$_3$Zr(0001) by scanning tunneling microscopy (STM), Auger electron microscopy, density functional theory (DFT). The well-annealed alloy shows perfect long-range chemical order. Occasional domain boundaries are probably caused nonstoichiometry. Pt$_3$Zr exhibits ABAC stacking along [0001]; only A-terminated surfaces seen STM, in agreement with DFT results showing a lower energy for A termination. further predicts stronger inward relaxation...