▎ 摘 要
Ultrathin graphite and few layer graphene fragments were obtained by mechanical exfoliation on copper surface and characterized by scanning electron microscopy, the energy dispersive X-ray spectroscopy and Raman spectroscopy. In order to achieve higher sensitivity on surface carbon layers the low-energy probing (1 key) by the energy dispersive spectroscopy was used. Data of the energy dispersive X-ray spectroscopy allows to obtain well distinct levels of carbon and to determine a minimum step level relating to one graphene layer. Raman spectra shows apparent contribution of the D-peak, indicating radiation damage after conventional medium electron microscopy investigations. The weak effect of radiation damage has also been revealed after low-energy (2 keV) observation and energy dispersive X-ray measurements using 1 key primary electron beam. (C) 2010 Elsevier B.V. All rights reserved.