2134/31991 Benjamin Maerz Benjamin Maerz Kenny Jolley Kenny Jolley Thomas James Marrow Thomas James Marrow Zhaoxia Zhou Zhaoxia Zhou Malcolm Heggie Malcolm Heggie Roger Smith Roger Smith Houzheng Wu Houzheng Wu Mesoscopic structure features in synthetic graphite Loughborough University 2018 Graphite Graphene Mesoscopic structure Crazy paving Carbon ring Elastic strain Chemical Sciences not elsewhere classified Mechanical Engineering 2018-02-26 09:32:22 Journal contribution https://repository.lboro.ac.uk/articles/journal_contribution/Mesoscopic_structure_features_in_synthetic_graphite/9235169 The mesocopic structure features in the coke fillers and binding carbon regions of a synthetic graphite grade have been examined by high resolution transmission electron microscopy (TEM) and Raman spectroscopy. Within the fillers, the three-dimensional structure is composed of crystal laminae with the basal plane dimensions (La) of hundreds nanometres, and thicknesses (Lc) of tens of nanometres. These laminae have a nearly perfect graphite structure with almost parallel c-axes, but their a-b planes are orientated randomly to form a “crazy paving” structure. A similar structure exists in the binding carbon regions, with a smaller La. Significantly bent laminae are widely seen in quinoline insoluble inclusions and the graphite regions developed around them. The La values measured by TEM are consistent with estimates from the intensity ratios of the D to G Raman peak in these regions. Atomistic modelling finds that the lowest energy interfaces in the crazy paving structure comprise 5, 6 and 7 member carbon rings. The bent laminae tend to maintain the 6 member rings, but are strained elastically. We suggest that a 7 member carbon ring leaves a cavity representing an arm-chair graphite edge contributing to the Raman spectra D peak.