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.