HRTEM images of selected CNTs. (a) Few-wall and multi-wall CNTs of various diameters, (b) a closed-tipped CNT, (c) CNT having a bamboo-like structure, (d) a double-wall CNT (indicated by an arrow), (e) CNT bundles, (f) a single CNT demonstrating a good crystallinity of the walls' structure, and (g, h, i) CNTs with the catalyst inclusions. The inset in Figure 7h shows a zoomed part of the encapsulated particle with the marked interplane distance.
Labunov et al. Nanoscale Research Letters 2012 7:102 doi:10.1186/1556-276X-7-102