X-ray diffraction measurements were carried out on 3 samples of disordered commercially produced C. Intensity data were converted to pair correlation functions via the Fourier transform. The results obtained showed that the structure of the studied samples consists of one-four graphite-like layers, stacked without spatial correlations. The size of the ordered regions was in the range of 9 to 16Å. The atomic arrangement within an individual layer could be described in terms of the paracrystalline ordering, in which lattice distortions propagate proportionally to the square root of interatomic distances. The paracrystalline structure was simulated by introducing the Stone-Wales defects (pair of 2 pentagons and 2 heptagons), randomly distributed in the network. The resulting structures were relaxed using the reactive empirical bond order potential for C-C interaction and the Lennard-Jones potential with parameters for interlayer interactions. Such defects lead to curvature of individual layers.

Structural Studies of Disordered Carbons by High-Energy X-Ray Diffraction. L.Hawełek, J.Kołoczek, A.Bródka, J.C.Dore, V.Honkimäki, A.Burian: Philosophical Magazine, 2007, 87[32], 4973-86