Search results
Results from the WOW.Com Content Network
Calcium graphite CaC 6 is obtained by immersing highly oriented pyrolytic graphite in liquid Li–Ca alloy for 10 days at 350 °C. The crystal structure of CaC 6 belongs to the R 3 m space group. The graphite interlayer distance increases upon Ca intercalation from 3.35 to 4.524 Å, and the carbon-carbon distance increases from 1.42 to 1.444 Å.
The expanded graphite can be used to make graphite foil or used directly as a "hot top" compound to insulate molten metal in a ladle or red-hot steel ingots and decrease heat loss, or as firestops fitted around a fire door or in sheet metal collars surrounding plastic pipe (during a fire, the graphite expands and chars to resist fire ...
In physics, Dirac cones are features that occur in some electronic band structures that describe unusual electron transport properties of materials like graphene and topological insulators. [ 1 ] [ 2 ] [ 3 ] In these materials, at energies near the Fermi level , the valence band and conduction band take the shape of the upper and lower halves ...
Highly oriented pyrolytic graphite (HOPG) is a highly pure and ordered form of synthetic graphite. It is characterised by a low mosaic spread angle, meaning that the individual graphite crystallites are well aligned with each other. The best HOPG samples have mosaic spreads of less than 1 degree.
A neutron's energy can vary widely, but it is not uncommon to have energies up to and exceeding 10 MeV (10,000,000 eV) in the centre of a nuclear reactor. A neutron with a significant amount of energy will create a displacement cascade in a matrix via elastic collisions. For example, a 1 MeV neutron striking graphite will create 900 ...
To produce expandable graphite, natural graphite flakes are treated in a bath of acid and oxidizing agent.Usually used oxidizing agents are hydrogen peroxide, potassium permanganate or chromic acid. Concentrated sulphuric acid or nitric acid are usually used as the compound to be incorporated, with the reaction taking place at temperatures of ...
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.
Annealed Pyrolytic Graphite (APG), also known as Thermally Annealed Pyrolytic Graphite (TPG), [1] is a form of synthetic graphite that offers excellent in-plane thermal conductivity. As with pyrolytic carbon or pyrolytic graphite (PG), APG is also low in mass, is electrically conductive , and offers diamagnetic properties that allow it to ...