Although surface diffusion is critical for many physical and chemical processes, including the epitaxial growth of crystals and heterogeneous catalysis, it is particularly challenging to directly study. Here, we estimate the carbon adatom migration barrier on freestanding monolayer graphene by quantifying its temperature-dependent electron knock-on damage. Due to the fast healing of vacancies by diffusing adatoms, the damage rate decreases with increasing temperature. By analyzing the observed damage rates at 300-1073 K using a model describing our finite scanning probe, we find a barrier of (0.33 \pm 0.03) eV.
@article{arxiv.2202.04485,
title = {Indirect measurement of the carbon adatom migration barrier on graphene},
author = {Andreas Postl and Pit Pascal Patrick Hilgert and Alexander Markevich and Jacob Madsen and Kimmo Mustonen and Jani Kotakoski and Toma Susi},
journal= {arXiv preprint arXiv:2202.04485},
year = {2022}
}
Comments
6 pages, 3 figures. Additionally, some supplemental material has been uploaded: 1 PDF, 1 Jupyter Notebook, 1 Python module, 3 data files in tabular form)