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In this article we present the first experimental evidence confirming a global presence of Buckminsterfullerene (C 60) in non-graphitizing polymeric carbon, along with its volume fraction calculations. Partially stacked carbon fragments featuring weak or strong curvatures constitute the structural units in non-graphitizing carbons. It has been proposed that a certain fraction of completely closed spherical fullerenes, such as C 60 , is also present in these materials. Strongly curved structures are not expected to exist in graphitizing carbons. We report on a Small Angle Neutron Scattering (SANS) investigation conducted at the Institut Laue-Langevin, Grenoble, France, that enables us to (i) quantify C 60 in a non-graphitizing carbon, (ii) investigate the evolution patterns of graphitizing and non-graphitizing carbons, and (iii) perform a detailed SANS analysis of pure crystalline C 60 in dry powder form. We also revisit the formation patterns of slightly larger structures (3–5 nm) such as graphitic crystallites and voids in both classes of polymeric carbon. These results provide a strong evidence in support of the fullerene-like microstructural models of non-graphitizing carbon, adding that the curved structural units are not just "fullerene-like", but also spherical fullerenes, C 60 in particular. [Display omitted] • Non-graphitizing carbons contain spherical fullerenes in addition to curved fragments. • Volume fraction of C 60 in carbon derived from a phenol-formaldehyde resin is ∼7%. • Graphitizing carbons do not contain spherical and closed fullerenes. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the results of SANS measurements of small samples using the very cold neutron (VCN) beam of the PF2 instrument at the Institut Laue Langevin (ILL), France. In addition to a classical SANS pinhole collimation, the experiment used a polarizing supermirror as a monochromator and a magnetic sextupole lens to focus the neutron beam in order to gain intensity and avoid any material in the neutron beam besides the sample. [Copyright &y& Elsevier]