Graphite stacking regularity

FIGURE 2.4 Translation of adjacent layers in hexagonal graphite to construct a regular stacking sequence. 

The tetrahedral connectivity leads to space-filling carbon polymers which are realized as defect-free ideal structures in diamond. The trigonal connectivity leads to sheets of carbon which are, in the defect-free variety, made up of hexagons leading to so-called graphene layers. The structures of graphite will result if these layers arc regularly stacked in the third dimension. In... 

The charge is fabricated into pellets about 4 in. diameter by 4 in. deep, which are stacked in a regular manner inside the graphite. 

For a 70 kg-scale reaction, 260 pellets are made, size 2 in. long by 2 in diameter. Each of these contains 265 g of uranium dioxide and 135 g of shredded calcium, i.e. a 25 per cent excess of the latter. These are stacked in a mild steel crucible, 42 in. deep by about 15 in. diameter, in regular staggered layers up to a height of 26 in. The crucible has previously been lined with a layer of lime, 1 in. thick on the walls and 3 in. thick at the base. A graphite lid is placed over the charge and covered with a I-in. layer of... 

As graphite designates that modification of the chemical element carbon, in which planar sheets of carbon atoms, each atom bound to three neighbors in a honeycomb-like structure, are stacked in a three-dimensional regular order, it is not correct to use for a single layer a term which includes the term graphite, which would imply a three-dimensional structure. The term graphene should be used only when the reactions, structural relations or other properties of individual layers are discussed. 

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