상세정보
학술지
Correlation between Micrometer-Scale Ripple Alignment and Atomic-Scale Crystallographic Orientation of Monolayer Graphene
- 발행일
- 201412
- 출처
- Scientific Reports, v.4, pp.1-5
- ISSN
- 2045-2322
- 출판사
- Nature Publishing Group
- 협약과제
- 14ZE1100, ETRI 창의연구실 사업, 손승원
- 초록
- Deformation normal to the surface is intrinsic in two-dimensional materials due to phononic thermal fluctuations at finite temperatures. Graphene's negative thermal expansion coefficient is generally explained by such an intrinsic property. Recently, friction measurements on graphene exfoliated on a silicon oxide surface revealed an anomalous anisotropy whose origin was believed to be the formation of ripple domains. Here, we uncover the atomistic origin of the observed friction domains using a cantilever torsion microscopy in conjunction with angle-resolved photoemission spectroscopy. We experimentally demonstrate that ripples on graphene are formed along the zigzag direction of the hexagonal lattice. The formation of zigzag directional ripple is consistent with our theoretical model that takes account of the atomic-scale bending stiffness of carbon-carbon bonds and the interaction of graphene with the substrate. The correlation between micrometer-scale ripple alignment and atomic-scale arrangement of exfoliated monolayer graphene is first discovered and suggests a practical tool for measuring lattice orientation of graphene.
- KSP 제안 키워드
- Atomic scale, Bending stiffness, Carbon-carbon, Crystallographic orientation, Finite temperatures, Intrinsic property, Lattice orientation, Monolayer graphene, Negative thermal expansion coefficient, Oxide surface, Silicon oxide