Open AccessМоделирование фазовых переходов графитов в алмазоподобные фазы
Author(s) -
Е.А. Беленков,
В.А. Грешняков
Publication year - 2018
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2018.07.46111.363
Subject(s) - diamond , tetragonal crystal system , graphite , graphene , materials science , hexagonal crystal system , diffraction , local density approximation , phase (matter) , condensed matter physics , phase transition , density functional theory , diamond cubic , crystallography , nanotechnology , chemistry , computational chemistry , optics , physics , composite material , quantum mechanics
The method of the density functional theory is used to study structural transformations between graphites and diamond-like phases. The calculations have been carried out in two approximations: a local density approximation and a generalized gradient approximation. It is found that the phase transitions of hexagonal graphene layers to a cubic diamond and diamond-like phases must occur at uniaxial compressions of ~57–71 GPa, whereas some diamond-like phases can be obtained from tetragonal graphene layers at significantly lower pressures of 32–52 GPa. The X-ray diffraction patterns have been calculated for the phase transition of graphite I 4_1/ amd to tetragonal LA 10 phase that takes place at the minimum pressure that can be used for experimental identification of these compounds.