Atomic-Scale Movement Induced in Nano-Ridges by Scanning Tunneling Microscopy on Epitaxial Graphene Grown on 4H-SiC(0001)

摘要

Nanoscale ridges in epitaxial multilayer graphene grown on the silicon faceof 4 degree off-cut 4H-SiC (0001) were found using scanning tunnelingmicroscopy (STM). These nano-ridges are only 0.1 nm high and 25-50 nm wide,making them much smaller than previously reported ridges. Atomic-resolution STMwas performed near and on top of the nano-ridges using a dual scanningtechnique in which forward and reverse images are simultaneously recorded. Anapparent 100% enlarged graphene lattice constant is observed along the leadingedge of the image for both directions. Horizontal movement of the graphene, dueto both an electrostatic attraction to the STM tip and weak bonding to thesubstrate, is thought to contribute to the results.