Title :
Scaling the dynamic electron scattering in HAADF-imaging the graphene sheets
Author :
Ding, W.F. ; Chen, T.S. ; Liao, K.M. ; He, L.B. ; Song, F.Q. ; Zhou, J.F. ; Wan, J.G. ; Wang, G.H. ; Han, Myungjin
Author_Institution :
Nat. Lab. of Solid State Microstructures, Nanjing Univ., Nanjing, China
Abstract :
Free-standing graphene sheets (GS) with several to over a hundred layers are prepared by splitting the expandable graphite. The raw material is firstly transferred to a heating chamber for the thermal flashing at 1500 οC in a hydrogen chamber. The expanded powder (1 mg) is then dispersed in 10 ml of the PmPV/DCE suspension for high-power sonication and further centrifugation. After drop-cast onto a holey Formvar film, the GSs are suspended on the grid. The electron scattering is carried out in a Tecnai F20 TEM/STEM with a field emission gun. A high-angle annular dark field (HAADF) detector is fitted to collect the scattered electrons with a tunable collecting angle. The quantitative STEM image simulation is carried out using amultislice algorithm [4].
Keywords :
casting; graphene; heating; scanning-transmission electron microscopy; sheet materials; transmission electron microscopy; C; Formvar film; Tecnai F20; amultislice algorithm; drop-cast; dynamic electron scattering; graphene sheets; heating chamber; high-angle annular dark field; high-power sonication; hydrogen chamber; scanning-transmission electron microscopy; temperature 1500 degC; thermal flashing; transmission electron microscopy;
Conference_Titel :
Vacuum Electron Sources Conference and Nanocarbon (IVESC), 2010 8th International
Conference_Location :
Nanjing
Print_ISBN :
978-1-4244-6645-0
DOI :
10.1109/IVESC.2010.5644169
