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Theoretical Investigation of Phase Transitions of Graphite and Cubic 3C Diamond Into Hexagonal 2H Diamond Under High Pressures
Author(s) -
Greshnyakov Vladimir A.,
Belenkov Evgeny A.,
Brzhezinskaya Maria M.
Publication year - 2019
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201800575
Subject(s) - diamond , graphite , materials science , material properties of diamond , orthorhombic crystal system , diamond type , hexagonal crystal system , diamond cubic , phase transition , graphene , crystallography , hexagonal phase , phase (matter) , carbon fibers , condensed matter physics , nanotechnology , composite material , crystal structure , composite number , chemistry , physics , organic chemistry
Possible techniques for experimentally obtaining hexagonal diamond are studied in the scope of the density functional theory method. It has been found that hexagonal diamond may be created as a result of structural transition at 61–68 GPa uniaxial compression from orthorhombic AB graphite and at 57–66 GPa from hexagonal AA graphite. Also the formation of hexagonal diamond is shown to take place in case of very strong (300–380 GPa) compression of cubic diamond. X‐ray and electron‐microscopic data on nanodiamonds from meteorite craters are analyzed for the presence of hexagonal diamond. The analysis shows that impact‐origin carbon materials do not contain pure cubic and hexagonal diamonds, and the layers of nascent crystals of diamond polytypes are randomly packed.