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.
- Helium atom scattering
Fields of Expertise
- Advanced Materials Science
Bahn, E., Tamtögl, A., Ellis, J., Allison, W., & Fouquet, P. (2016). Structure and dynamics investigations of a partially hydrogenated graphene/Ni(111) surface. Carbon, 114, 504. https://doi.org/10.1016/j.carbon.2016.12.055