Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul 143-701, Korea.
Science. 2011 Jul 29;333(6042):607-10. doi: 10.1126/science.1207110. Epub 2011 Jun 30.
Graphene produced by exfoliation has not been able to provide an ideal graphene with performance comparable to that predicted by theory, and structural and/or electronic defects have been proposed as one cause of reduced performance. We report the observation of domains on exfoliated monolayer graphene that differ by their friction characteristics, as measured by friction force microscopy. Angle-dependent scanning revealed friction anisotropy with a periodicity of 180° on each friction domain. The friction anisotropy decreased as the applied load increased. We propose that the domains arise from ripple distortions that give rise to anisotropic friction in each domain as a result of the anisotropic puckering of the graphene.
剥离法制备的石墨烯未能提供性能可与理论预测相媲美的理想石墨烯，而结构和/或电子缺陷被认为是性能降低的一个原因。我们报告了在剥离的单层石墨烯中观察到的具有不同摩擦特性的畴，其通过摩擦力显微镜测量。角度依赖扫描显示每个摩擦畴上具有 180°周期性的摩擦各向异性。随着外加负载的增加，摩擦各向异性减小。我们提出这些畴是由波纹变形引起的，由于石墨烯的各向异性外鼓，导致每个畴中出现各向异性摩擦。
