▎ 摘　　要

We examined the number of layers in graphene using Raman microscopy and investigated the interlayer interactions by understanding the layer stacking through the E*(low) mode measured in Raman spectroscopy designed for low-frequency observation. The number of layers in Raman image was determined from the G/2D intensity ratio, and the interlayer stacking for 2, 3 and 4 layers was understood from the positions of the E*(low) mode. While most part of sample showed AB stacking, a small area showed random stacking of layers. Low-frequency Raman spectroscopy revealed that such sample area was consisted of weakly interacted random stacking of graphene layers. (C) 2012 Elsevier B.V. All rights reserved.