High resolution TEM study of WS2 nanotubes

Abstract

Closed capped WS2 nanotubes with diameters from 30 to 110 nm are studied by high resolution transmission electron microscopy (HRTEM). The tubes exhibit preferentially a hexagonal stacking order. Atomic resolution images of a 30 nm diameter tube reveal a zigzag chirality. A lattice expansion in c-axis direction of ≤11% is found within the outermost triple layers. The tube caps often display regular polygon angles. Structural defects like grain boundaries, nonplanar triple layers, dislocations, platelet-like fragments, terraces, and amorphous precipitates are identified. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.