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February 05, 2010

P doped Graphane Calculations Predict Will Superconduct at 90K


Graphane is graphene with a lot of hydrogen. Graphene is two dimensional sheet of carbon. Graphane was made for the first time only last year at the University of Manchester. P-doped diamond nanowires might have similar properties. Copper oxides superconduct in an entirely different way to conventional BCS superconductors (after Bardeen, Cooper and Schrieffer, who worked out the theory behind them). p-doped graphane should superconduct in the same way as the old fashioned BCS superconductors.

6 page pdf arxiv - Doped graphane: a prototype high-T
c electron-phonon superconductor


We show by first-principles calculations that p-doped graphane is a conventional superconductor with a critical temperature (Tc) above the boiling point of liquid nitrogen. The unique strength of the chemical bonds between carbon atoms and the large density of electronic states at the Fermi energy arising from the reduced dimensionality synergetically push Tc above 90K, and give rise to large Kohn anomalies in the optical phonon dispersions. As evidence of graphane was recently reported, and doping of related materials such as graphene, diamond and carbon nanostructures is well established, superconducting graphane may be feasible.

Technology Review arxiv blog has coverage

They calculate that p-doped graphane fits the bill exactly and should superconduct in the old-fashioned BCS way at 90K. What's more they say there are hints that p-doped diamond nanowires might have similar properties.

Various groups are already playing around with doped diamond nanowires.



p-doping at wikipedia

A P-type semiconductor (P for Positive) is obtained by carrying out a process of doping, that is adding a certain type of atoms to the semiconductor in order to increase the number of free charge carriers (in this case positive).

When the doping material is added, it takes away (accepts) weakly-bound outer electrons from the semiconductor atoms. This type of doping agent is also known as an acceptor material and the vacancy left behind by the electron is known as a hole.

The purpose of P-type doping is to create an abundance of holes.



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