Four superhard carbon allotropes: First-principle study

Abstract

Using a generalized genetic algorithm, we propose four new sp3 carbon allotropes with 5-6-7 (5-6-7-type Z-ACA and Z-CACB) or 4-6-8(4-6-8-type Z4-A3B1 and A4-A2B2) carbon rings. Their stability, mechanical and electronic properties are systematically studied using first-principles method. We find that all these four carbon allotropes show amazing stability in comparison with recently proposed carbon phases. Both ZACA and Z-CACB are direct-band-gap semiconductors with band gaps of 2.261 eV and 4.196 eV, respectively. Whereas Z4-A3B1 and A4-A2B2 are indirect-band-gap semiconductors with band gaps of 3.105 eV and 3.271 eV, respectively. Their mechanical properties reveal that all these four carbon allotropes are superhard materials comparable to diamond.

6 pages, 4 figures, submit to PCCP on 21-Feb-2012

References in corpus (3)

• Crystal Structure Prediction via Particle Swarm Optimization
• Molecular geometry optimization with a genetic algorithm
• Superhard sp3 carbon allotropes with odd and even ring topologies

Cited by in corpus (6)

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• Topological carbon materials: a new perspective
• Direct and quasi-direct band gap silicon allotropes with remarkable stability
• Direct band gap carbon superlattices with efficient optical transition
• Detonation-induced transformation of graphite to hexagonal diamond
• Three-dimensional honeycomb carbon: Junction line distortion and novel emergent fermions