Dresden 2014 – scientific programme

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KR: Fachgruppe Kristallographie

KR 8: Poster Crystallography

KR 8.4: Poster

Wednesday, April 2, 2014, 17:00–19:30, P4

Transmission Kikuchi Diffraction and Selected Area Electron Diffraction studies of WS₂ nanotubes — Andrey Chkanov¹, Azat Khadiev¹, •Nathanael Jöhrmann², Dmitry Pashin¹, and Michael Hietschold² — ¹Kazan National Research Technical University named after A.N. Tupolev, Nanotechnology in Electronics Department, Kazan, Russia — ²Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz, Germany

Investigations of nanotubes have shown that tubes may differ not only in chemical composition but also in structure. Selected area electron diffraction (SAED) in TEM is a well-established method that allows distinguishing structural parameters of single nanotubes. However in the case of single tubes deposited on a bulk substrate TEM methods do not work. An alternative might be electron backscatter diffraction (EBSD). Clear understanding of peculiarities of Kikuchi diffraction found on nanotubes requires comparative studies. Using SAED and transmission Kikuchi diffraction (TKD) allows a comparison between a SAED pattern and an EBSD like Kikuchi diffraction pattern obtained from one and the same tube lying on a TEM grid.

We combine SAED and TKD measurements with pattern simulations for structural analysis of WS₂ nanotubes. SAED studies allowed determining parameters of the unit cell and chiral angle of the tube. In the TKD studies a peculiar intense band was observed for most nanotubes, which might also contain information about the chiral angle. In some cases two TKD patterns seemed to overlap. Structure models were proposed to explain this effect.