MIXED LAYERING IN DISORDERED SRI-LANKA GRAPHITE

Rotational disorder is common to two millimeter-sized samples of Sri Lanka disordered graphite which also contains domains of the new carbon phase. Chemical disorder in the samples is inferred from d002 interplanar and lattice fringe spacings that are part of three distinct populations, centered at about d002 = 0.348 nm, 0.371 nm, and 0.45 nm and from short-range periodic stacking in lattice-fringe ribbons. The aromatic and alicyclic structures form metastable carbon-rich sheets with variable (100 x C)/(C + H + O + N) ratio. The chemical and structural data are consistent with a model of mixed-layered carbon-rich, C-(H,O,N), material. Mixed-layered carbons include previously reported carbynes which are re-interpreted as carbon-rich, pre-graphitic C-(H,O,N) material. Mixed layering of chemically impure, carbon-rich pre-graphite sheets reflects complex interactions of physical and chemical parameters during carbonisation and graphitisation of natural terrestrial carbonaceous material.