Graphene ‘relative’ discovered
21 Sep 2015 by hqhtjtwqmt.d hqhtjtwqmt.d
Scientists have found a new two dimensional material that resembles the structure of graphene.
An international team of researchers led by the Moscow Institute of Physics and Technology (MIPT) used computer simulations to predict the existence of a new two dimensional carbon material similar to graphene that they call phagraphene.
“Unlike graphene, a hexagonal honeycomb structure with atoms of carbon at its junctions, phagraphene consists of penta-, hexa- and heptagonal carbon rings. Its name comes from a contraction of Penta-Hexa-hepta-graphene,” said research leader Professor Artyom Oganov from MIPT.
In the study, published in the journal Nano Letters, the team used an algorithm – known as USPEX – which predicted that the structure of the new material is composed of 5-carbon, 6-carbon and 7-carbon rings. They also found that the electronic structure of phagraphene has distorted Dirac cones – energy bands that form two circular cones, connected with one another at their extremities and seem to have a strange effect on the properties of electrons.
Professor Oganov said: “In phagraphene, due to the different number of atoms in the rings, the Dirac cones are ‘inclined’. That is why the velocity of electrons in it depends on the direction. This is not the case in graphene. It would be very interesting for future practical use to see where it will be useful to vary the electron velocity.”
The researchers believe that the new material possesses similar physical properties to those of graphene and hope the new material will be useful for flexible electronic devices, transistors, solar batteries and display units.
Paper: http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b02512
