English

C5 as simplest ultrahard allotrope with mixed sp2/sp3 carbon hybridizations from first principles

Materials Science 2022-10-11 v1

Abstract

From crystal chemistry rationale and density functional DFT calculations, novel tetragonal carbon C5 is proposed as simplest ultrahard allotrope with mixed hybrid carbon hybridizations (sp2 - sp3). Novel pentacarbon is identified as cohesive and stable both dynamically and mechanically. Whereas charge density is localized about tetrahedral C-sp3, it is found delocalized around trigonal C-sp2 resulting in metallic behavior. The anisotropic structure characteristics caused by the aligned trigonal carbon along the tetragonal c-axis provide high Vickers hardness with a magnitude close to diamond

Keywords

Cite

@article{arxiv.2210.04210,
  title  = {C5 as simplest ultrahard allotrope with mixed sp2/sp3 carbon hybridizations from first principles},
  author = {Samir F Matar},
  journal= {arXiv preprint arXiv:2210.04210},
  year   = {2022}
}

Comments

15 pages, 26 refs, 2 Tables, 5 figs. arXiv admin note: text overlap with arXiv:2206.05918