Carbon nitride frameworks and dense crystalline polymorphs

Authors

C J. Pickard, University College LondonFollow
Ashkan Salamat, University of Nevada, Las VegasFollow
M J. Bojdys, University in Prague
R J. Needs, Cavendish Laboratory
P F. McMillan, University College LondonFollow

Document Type

Article

Publication Date

1-1-2016

Publication Title

Physical Review B

Volume

94

Issue

9

Abstract

We used ab initio random structure searching (AIRSS) to investigate polymorphism in C3N4 carbon nitride as a function of pressure. Our calculations reveal new framework structures, including a particularly stable chiral polymorph of space group P43212 containing mixed sp2 and sp3 bonding, that we have produced experimentally and recovered to ambient conditions. As pressure is increased a sequence of structures with fully sp3-bonded C atoms and three-fold-coordinated N atoms is predicted, culminating in a dense Pnma phase above 250 GPa. Beyond 650 GPa we find that C3N4 becomes unstable to decomposition into diamond and pyrite-structured CN2. © 2016 American Physical Society.

Language

English

Repository Citation

Pickard, C. J., Salamat, A., Bojdys, M. J., Needs, R. J., McMillan, P. F. (2016). Carbon nitride frameworks and dense crystalline polymorphs. Physical Review B, 94(9),
http://dx.doi.org/10.1103/PhysRevB.94.094104