Using helium-3 atom scattering, we have studied the adsorption kinetics, the structure and the diffusional dynamics of atomic hydrogen on the surface of a graphene monolayer on Ni(111). Diffraction measurements reveal a 4∘ rotated rectangular hydrogen overstructure. Hydrogen adsorption and desorption exhibit activation barriers of Ea=(89±7)meV and Ed=(1.8±0.2)eV, respectively. Helium-3 spin-echo measurements showed no decay of the spatial correlation function (or intermediate scattering function) within the time range of the spectrometer. Hence, we are able to set lower limits for a possible hydrogen surface diffusion rate.
@article{arxiv.2212.07159,
title = {Structure and dynamics investigations of a partially hydrogenated graphene/Ni(111) surface},
author = {Emanuel Bahn and Anton Tamtögl and John Ellis and William Allison and Peter Fouquet},
journal= {arXiv preprint arXiv:2212.07159},
year = {2022}
}