▎ 摘　　要

Using the classical molecular dynamics and the simulated annealing techniques, we show that monolayer graphene nanoribbons (GNRs) on 6H-SiC(0001) surface form atomic scale rippled structures. From the analysis of atomic configurations, two different types of rippled structures in GNRs can be identified, namely, the periodic rippled structure at room temperature or even at lower temperatures and random ripples at high temperatures. The dependence of microscopic roughness of the ripples on temperature and size are studied through analyzing the covalent bonding inhomogeneities in bond-length and bond- angle distributions. Our results provide atomic-level information about the rippled GNRs on SiC substrate, which is useful not only for understanding the structure and stability of monolayer GNRs but also for future applications of GNRs in nanoelectronics. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3032895]