Multi‐wall carbon nanotubes investigated by positron annihilation techniques and microscopies for further production handling

Autor: G. Huhn, M. V. Nhon, L. T. Son, Tran Duy Tap, Károly Havancsák, T. Q. Dung, Z. E. Horváth, A. T. Luu, N. D. Thanh, P. T. Phuc, Károly Lázár, Zs. Kajcsos
Rok vydání: 2009
Předmět:
Zdroj: physica status solidi c. 6:2578-2581
ISSN: 1610-1642
1862-6351
Popis: Multi-wall carbon nanotube samples with various tube diameters produced by Thermal Chemical Vapor Deposition technique using various catalysts were studied by various microscopic methods and positron annihilation spectroscopy (PAS) with the aim of assessing the applicability of these methods for structural studies in these novel materials. Specifically, positron lifetime (LT) and Doppler broadening (DB) techniques, transmission electron microscopy (TEM) and atomic force microscopy (AFM) were employed, on iron-containing samples Mossbauer spectroscopy was also utilized. The PAS measurements were carried out on densely packed powder samples and on samples pressed into pills in atmospheric pressure and in vacuum as well. The lifetime values could be interpreted by assuming trapping of positrons, the low contribution from longer-living trapped positronium can be probably related to defects on walls of the tubes. Possibility of correlation of LT and DB data with the nanotube sizes and sample composition was also considered. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Databáze: OpenAIRE