The structure and continuous stoichiometry change of 1DTbBr(x)@SWCNTs

Author(s)
N. A. Kiselev, A. S. Kumskov, V. G. Zhigalina, A. L. Vasiliev, J. Sloan, N. S. Falaleev, N. I. Verbitskiy, A. A. Eliseev
Abstract

HRTEM and HAADF STEM of 1DTbBr(x)@SWCNT meta-nanotubes reveal three structural modifications of 1D nanocrystals within single wall carbon nanotube channels attributed to a different stoichiometry of the guest crystal. For SWCNTs with diameters D-m > 1.4 nm a most complete tetragonal unit cell is observed. When crystallization occurs inside SWCNT with D-m <1.4 nm 1D TbBrx crystal deforms a nanotube to elliptical shape in cross section. In this case the 1D crystal unit cell becomes monoclinic, with possible loss of a part of bromine atoms. Two modifications of a monoclinic unit cell appear. One of them is characterized by single or pair vacancies in the structure of the 1D crystal. Another structure is explained by peripheral and central bromine atoms loss. An appearance of such modifications can be stimulated by electron irradiation. The loss of bromine atoms is in agreement with chemical analysis data. Electronic properties of obtained meta-nanotubes are investigated using optical absorption and Raman spectroscopy. It is shown that intercalation of terbium bromide into SWCNTs leads to acceptor doping of SWCNTs. According to local EDX analysis and elemental mapping this doping can arise from significant stoichiometry change in 1D nanocrystal indicating an average Tb:Br atomic ratio of 1:2.8 0.1.

Organisation(s)
Electronic Properties of Materials
External organisation(s)
Russian Academy of Sciences, Russian Research Centre Kurchatov Institute, University of Warwick, Anuchin Research Institute and Museum of Anthropology, Universität zu Köln
Journal
Journal of Microscopy
Volume
262
Pages
92-101
No. of pages
10
ISSN
0022-2720
DOI
https://doi.org/10.1111/jmi.12348
Publication date
04-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
103042 Electron microscopy, 210004 Nanomaterials
Keywords
ASJC Scopus subject areas
Pathology and Forensic Medicine, Histology
Portal url
https://ucris.univie.ac.at/portal/en/publications/the-structure-and-continuous-stoichiometry-change-of-1dtbbrxswcnts(add7ae1a-3297-4e7d-86a8-997ea2c1d3ee).html