Microsc. Microanal. Microstruct. 6, 405-413 (1995)
DOI: 10.1051/mmm:1995130

Quantitative Elemental Distribution Image of a Carbon Nanotube

Hiroki Kurata, Seiji Isoda et Takashi Kobayashi

Institute for Chemical Research, Kyoto University, Uji, Kyoto 611, Japan

Abstract
Energy-filtering transmission electron microscopy was applied to carbon nanotubes in order to investigate quantitative property of elemental maps obtained by inelastically scattered electrons corresponding to the carbon K-edge. A 1 MeV high-resolution electron microscope (JEOL, ARM-1000) equipped with a GATAN imaging filter was employed. Because of the cylindrical structure of nanotubes the number of carbon atoms contributing to the image changes across the tube axis. We could detect the contrast difference due to 20 carbon atoms in the carbon distribution image of 6 layers tube. Furthermore, we examined the carbon mapping from a conical tip region with progressive closure of carbon layers, where an intensity profile clearly distinguishes the difference of 6 graphene sheets. From the consideration of signal-to-noise ratio, the detection limit is concluded to be less than 22 carbon atoms in the present experimental conditions.

PACS
6146 - Structure of solid clusters, nanoparticles, and nanostructured materials.

Key words
fullerenes -- transmission electron microscopy -- quantitative elemental distribution image -- carbon nanotube -- energy filtering transmission electron microscopy -- elemental maps -- inelastically scattered electrons -- GATAN imaging filter -- cylindrical structure -- contrast difference -- conical tip region -- graphene sheets -- signal to noise ratio -- 1 MeV -- C


© EDP Sciences 1995