Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 18: Computational Materials Modelling - Phase Stability I
MM 18.5: Vortrag
Dienstag, 12. März 2013, 11:15–11:30, H24
Prediction of a hybrid graphene-diamond like phase — •Silvia Bahmann, Torsten Weißbach, and Jens Kortus — TU Bergakademie Freiberg, Institute of Theoretical Physics, D-09596 Freiberg, Germany
The crystal structure contains the most important information about a crystalline solid. Therefore, predicting it from first principles by just specifying the chemical composition has been long pursued. Increasing computer power in the last decade made it possible to explore the huge search space (3N + 3 dimensions where N is the number of atoms) of unknown crystal structures using density functional theory.
We applied an evolutionary strategy that uses the main features of natural evolution namely recombination, mutation, selection and the survival of the fittest and found a new hybrid graphene-diamond like phase. Our structure can be described as crossing graphene sheets that form nearly rectangular tubular pores. The atoms at the crossing lines show nearly perfect tetrahedral coordination whereas the ones in between exhibit sp3 bonding. Crossed graphene is shown to be dynamically stable with respect to phonons and elastic constants. The latter also point out the close relation to graphite/graphene. By inspecting the eletronic structure similarities to graphene also become visible.