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

fYear

2010

fDate

14-16 Oct. 2010

Firstpage

644

Lastpage

645

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;

fLanguage

English

Publisher

ieee

Conference_Titel

Vacuum Electron Sources Conference and Nanocarbon (IVESC), 2010 8th International

Conference_Location

Nanjing

Print_ISBN

978-1-4244-6645-0

Type

conf

DOI

10.1109/IVESC.2010.5644169

Filename

5644169