▎ 摘　　要

In this paper, we have used low temperature scanning tunneling microscopy and spectroscopy (LT-STM/STS) to study zigzag or armchair edges of epitaxial graphene on 6H-SiC (0001). The monolayer carbon structures exhibit occasionally one-dimensional ridge (1D) in close vicinity to step edge. This ridge exhibits different edges orientations in armchair zigzag transition which give rise to different local density of states (LDOS) along this ID structure. This ridge formation is likely explained by residual compressive in-plane stresses. (C) 2012 Elsevier B.V. All rights reserved.