9 research outputs found
Commensurate-incommensurate transition of monolayer krypton on graphite by helium-atom scattering
Plant-Mediated Synthesis of AgâPd Alloy Nanoparticles and Their Application as Catalyst toward Selective Hydrogenation
Theory and simulation of epitaxial rotation. Light particles adsorbed on graphite
We present a theory and Monte Carlo simulations of adsorbed particles on a corrugated substrate. We have focused on the case of rare gases and light molecules,
H
2
and
D
2
, adsorbed on graphite. The competition between the particle-particle and particle-substrate interactions gives rise to frustration phenomena. From our model predictions for the epitaxial rotation angle of the adsorbed phases are determined. Our results extend and unify previously known descriptions. We have studied as a function of temperature and coverage the phase diagrams, especially the intermediate phases appearing between the commensurate and incommensurate phase for the adsorbed systems. From our simulations and our theory, we are able to understand the Îł phase of
D
2
as an ordered phase stabilized by disorder. It can be described as a 2q-modulated structure. In agreement with the experiments, we have also found a modulated 4Ă4 structure. Energy, structure-factor intensities, peak positions, and epitaxial rotation angles as a function of temperature and coverage have been determined from the simulations. Good agreement with theory and experimental data is found