Atomic-scale topography of epitaxial multilayer graphene grown on 4H-SiC(0001) was investigated using scanning tunneling microscopy (STM). Bunched nano-ridges ten times smaller than previously recorded were observed throughout the surface, the morphology of which was systematically altered using a relatively new technique called electrostatic-manipulation scanning tunneling microscopy. Transformed graphene formations sometimes spontaneously returned to their original morphology, while others permanently changed. Using an electrostatic model, we calculate that a force up to ~5 nN was exerted by the STM tip, and an energy of around 10 eV was required to alter the geometry of a ~100 X 200 nm^2 area.
@article{arxiv.1501.06903,
title = {Graphene Manipulation on 4H-SiC(0001) Using Scanning Tunneling Microscopy},
author = {P. Xu and M. L. Ackerman and S. D. Barber and J. K. Schoelz and D. Qi and P. M. Thibado and V. D. Wheeler and L. O. Nyakiti and R. L. Myers-Ward and C. R. Eddy, and D. K. Gaskill},
journal= {arXiv preprint arXiv:1501.06903},
year = {2015}
}