The indirect interaction between adatom pairs on the (100) surface of a simple-cubic tight-binding solid is investigated within molecular-orbital approach. A general scheme for calculating surface-density-of-states change and energy one two single-level adatoms presented, contact (and correction) made with Grimley's formulation. method permits binding above atoms, at bridge sites, or centered positions, yields as function band filling, level, hopping potential $V$ an nearest atom(s)....

Exposure to oxygen at 300–340 °C results in triangular etch pits with uniform orientation on the surfaces of atomically thin molybdenum disulfide (MoS2), indicating anisotropic etching terminating lattice planes. The grow laterally oxidation time. density scarcely depends time, temperature, and MoS2 thickness but varies significantly from sample sample, that is initiated native defect sites basal plane surface rather than activated by substrate effects such as charged impurities or...

Using scanning tunneling microscopy, we have quantitatively characterized the configurations of steps on vicinal Si(111) surfaces misoriented by 1.2\ifmmode^\circ\else\textdegree\fi{} and 2.3\ifmmode^\circ\else\textdegree\fi{} towards [1\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasciimacron\fi{} 2] direction. The measured terrace-width distributions are strongly peaked, consistent with predictions for thermally wandering steps. However, much narrower than predicted simple...

Abstract Progress in the development of theory two chemisorbed atoms has been hindered by very low symmetry problem. Mono-layers adatoms are simplest since they have full two-dimensional substrate. Going to a (2 × 1) or 2) adlayer, which doubles size surface primitive cell, quadruples secular matrix, raising computer time even more. At other end scale, single adatom (in symmetric site) will at least point With jellium as substrate, this increases rotational and translational symmetry....

The morphology of surfaces arbitrary orientation in the presence step and kink Ehrlich-Schwoebel effects (SESE KESE) during growth is studied within framework a model which steps are continuous lines, illustrated by simple solid-on-solid model. For vicinal KESE induces an instability often stronger than that from SESE. possibility stable flow analyzed. Fluctuations can shift stability threshold. also mound formation.

In recent observations of Brownian motion islands adsorbed atoms and vacancies with mean radius $R$, the cluster diffusion constant varies as ${R}^{\ensuremath{-}1}$ ${R}^{\ensuremath{-}2}$. From an analytical Langevin description cluster's steplike boundary, we find three cases, ${R}^{\ensuremath{-}1}$, ${R}^{\ensuremath{-}2}$, ${R}^{\ensuremath{-}3}$, corresponding to microscopic surface mass-transport mechanisms straight steps. We thereby provide a unified treatment dynamics steps...

We report on the first direct measurement of change surface stress in reconstruction Au(111) and Au(100) surfaces. For both surfaces relaxes intrinsic tensile stress, by 22% 5%, respectively. A discussion data Frenkel-Kontorova model shows that energy gain due to is not quite large enough make reconstructed phase energetically favored without formation secondary herringbone structure solitons. On surface, elastic strain clearly insufficient cause reconstruct.

Step motion on surfaces can now be measured quantitatively. We present a formalism for analyzing equilibrium step fluctuations and apply it to real-time reflection electron microscope observations of Si(111). The time correlation functions the positions their Fourier components are compared with predictions from Langevin equations two extreme mechanisms motion: edge diffusion terrace exchange. At 900 \ifmmode^\circ\else\textdegree\fi{}C, dominant mechanism is exchange constant...

In recent observations of Brownian motion islands adsorbed atoms and vacancies with mean radius R, the cluster diffusion constant ${\mathit{D}}_{\mathit{c}}$ varies as ${\mathit{R}}^{\mathrm{\ensuremath{-}}1}$ ${\mathit{R}}^{\mathrm{\ensuremath{-}}2}$. From an analytical continuum description cluster's steplike boundary, we find a single Langevin equation for rather than three special cases. this determine correlation function ${\mathit{G}}_{\mathit{sh}}$ fluctuations shape around assumed...

We report the first determination of critical exponents for a chemisorbed overlayer, using low-energy electron diffraction. examine order-disorder transition $p(2\ifmmode\times\else\texttimes\fi{}2)$ oxygen on (111) surface nickel. This study is behavior two-dimensional system in four-state Potts universality class. From measured diffraction-beam profiles, we extract $\ensuremath{\beta}$, $\ensuremath{\gamma}$, and $\ensuremath{\nu}$. Discussion disparity between our results predicted...

For the terrace-step-kink model of a stepped surface, distribution P(L) terrace widths L is calculated at low temperature by mapping problem onto one-dimensional free-fermion model. In this approximation, only energetic interaction between steps hard-core repulsion. A skewed with parabolic rise and Gaussian tail found; exact asymptotic forms are displayed. By plotting 〈L〉P(L) vs L/〈L〉, we obtain ``universal'' curve nearly independent average width 〈L〉. With use scaling property, analytic...

We study theoretically the equilibrium fluctuations of steps on vicinal surfaces. From an analytical continuum description step edge, we find a single Langevin equation governing motion isolated around its position that includes attachment/detachment atoms, diffusion over terrace, along and evaporation. then extend this approach to treat array steps, i.e., surface. also present, in appendix, alternative formalism which detachment terrace step-edge can take place independently. In established...

In island nucleation and growth, the distribution of capture zones (in essence proximity cells) can be described by a simple expression generalizing Wigner surmise (power-law rise, Gaussian decay) from random matrix theory that accounts for spacing distributions in host fluctuation phenomena. Its single adjustable parameter, power-law exponent, simply related to critical nucleus growth models substrate dimensionality. We compare with extensive published kinetic Monte Carlo data limited...

Using a van der Waals density functional (vdW-DF) [Phys. Rev. Lett. 92, 246401 (2004)], we perform ab initio calculations for the adsorption energy of benzene (Bz) on Cu(111) as function lateral position and height. We find that vdW-DF inclusion nonlocal correlations (responsible dispersive interactions) changes relative stability eight binding-position options increases binding by over an order magnitude, achieving good agreement with experiment. The admolecules can move almost freely along...

Single-layer graphene (SLG) supported on SiO2 shows anomalously large chemical reactivity compared to thicker graphene, with charge inhomogeneity-induced potential fluctuations or topographic corrugations proposed as the cause. Here we systematically probe oxidative of substrates different surface roughnesses and charged impurity densities: hexagonal boron nitride (hBN), mica, thermally grown Si, nanoparticle thin films. SLG low trap density hBN is not etched little doping after oxygen...

Thin membranes exhibit complex responses to external forces or geometrical constraints. A familiar example is the wrinkling, exhibited by human skin, plant leaves, and fabrics, resulting from relative ease of bending versus stretching. Here, we study wrinkling graphene, thinnest stiffest known membrane, deposited on a silica substrate decorated with nanoparticles. At small nanoparticle density monolayer graphene adheres substrate, detached only in regions around With increasing density,...

We have used electron diffraction to study submonolayers of Se adsorbed on Ni(100); $p(2\ifmmode\times\else\texttimes\fi{}2)$, $c(2\ifmmode\times\else\texttimes\fi{}2)$, and disordered phases were observed the boundaries between them located. Symmetry arguments indicate that phase diagram belongs universality class Ashkin-Teller model allow us predict critical behavior near at multicritical point where they meet. Our lattice-gas-model calculations support these results. The predicted...

We expound the idea that as a probe of short-range order, low-energy electron diffraction can be used to study energy singularity associated with surface phase transitions. demonstrate its feasibility by performing Monte Carlo simulations on two triangular lattice gases second-order transitions in universality classes distinguished critical exponent \ensuremath{\alpha}: The first has (\ensuremath{\surd}3 \ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}3...