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Another high-temperature lubricant, hexagonal boron nitride, has the same molecular structure as graphite. It is sometimes called white graphite, due to its similar properties. When a large number of crystallographic defects bind its planes together, graphite loses its lubrication properties and becomes what is known as pyrolytic graphite.
Graphene (/ ˈ ɡ r æ f iː n /) [1] is a carbon allotrope consisting of a single layer of atoms arranged in a honeycomb planar nanostructure. [2] [3] The name "graphene" is derived from "graphite" and the suffix -ene, indicating the presence of double bonds within the carbon structure.
The Laves graph or K 4 crystal is a theoretically predicted three-dimensional crystalline metastable carbon structure in which each carbon atom is bonded to three others, at 120° angles (like graphite), but where the bond planes of adjacent layers lie at an angle of 70.5°, rather than coinciding.
Many solids, e.g. graphite, adopt low-dimensional structures, in which case the layers (2-D) or chains (1-D) should be shown. Some inorganic solids dissociate - or crack - into molecular species heating or upon dissolving, e.g. Aluminium chloride. In such cases it is helpful to depict both the molecular and the nonmolecular forms.
The structure of graphite was solved in 1916 [40] by the related method of powder diffraction, [41] which was developed by Peter Debye and Paul Scherrer and, independently, by Albert Hull in 1917. [42] The structure of graphite was determined from single-crystal diffraction in 1924 by two groups independently.
Graphitization can be observed in various contexts. For example, it occurs naturally during the formation of certain types of coal or graphite in the Earth's crust.It can also be artificially induced during the manufacture of specific carbon materials, such as graphite electrodes used in fuel cells, nuclear reactors or metallurgical applications.
Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in crystalline structure.. Allotropy or allotropism (from Ancient Greek ἄλλος (allos) ' other ' and τρόπος (tropos) ' manner, form ') is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements.
Oberlin and colleagues emphasised the role of basic structural units (BSU), made of planar aromatic structures consisting of less than 10–20 rings, with four layers or fewer. Cross-linking between the BSUs in non-graphitizing carbons prevents graphitization . [ 3 ]