Nano-scale structural features of stratified hydrocarbon films formed at interaction of plasma with surface in T-10 tokamak

Abstract

Hydrocarbon films and flakes (i.e. free standing films) with high atomic deuterium to carbon ratio formed at deuterium plasma discharges in T-10 tokamak are non-crystalline. They contain structure elements of cluster/nanopore type with typical sizes of about 1 nm and interplane distances between X-ray scattering structures of 0.7, 0.24 and 0.12 nm. Structural sp2- carbon states were found mainly on the wall side of flakes, and sp 3-hybridized carbon states - on their plasma side. In situ monitoring of films growth and hydrogen isotope accumulation in them by means of Fourier-transform infrared (FT-IR) spectroscopy is proposed. The computational modeling of X-ray scattering by random ensembles of carbon nanostructures of various types suggests that a strong peak of X-ray diffraction (XRD) intensity may be caused by the toroids (toroidal carbon nanotubes) with torus radius of about 1 nm. © 2010 Elsevier B.V. All rights reserved.