Portal de Periódicos da CAPES

Body-Centered Tetragonal C 4 : A Viable s p 3 Carbon Allotrope

2010; American Physical Society; Volume: 104; Issue: 12 Linguagem: Inglês

10.1103/physrevlett.104.125504

1092-0145

Koichiro Umemoto, Renata M. Wentzcovitch, Susumu Saito, Takashi Miyake,

Diamond and Carbon-based Materials Research

We have investigated by first principles the electronic, vibrational, and structural properties of bct C4, a new form of crystalline sp{3} carbon recently found in molecular dynamics simulations of carbon nanotubes under pressure. This phase is transparent, dynamically stable at zero pressure, and more stable than graphite beyond 18.6 GPa. Coexistence of bct C4 with M carbon can explain better the x-ray diffraction pattern of a transparent and hard phase of carbon produced by the cold compression of graphite. Its structure appears to be intermediate between that of graphite and hexagonal diamond. These facts suggest that bct C4 is an accessible form of sp{3} carbon along the graphite-to-hexagonal diamond transformation path.