The dislocation structure of diamond crystals grown on seeds in the Mg-C system

Alexander F. Khokhryakov, Denis V. Nechaev, Yuri N. Palyanov, Konstantin E. Kuper

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

The dislocation structure of diamond crystals grown in the Mg-C system at a pressure of 7 GPa and temperatures of 1800–1900 °C is studied by X-ray topography and selective etching. According to the selective etching data, diamond crystals have two types of dislocations whose outputs on the {100} faces of crystal are associated with two types of etch pits. It has been demonstrated that the etch pits with the side wall inclination angle of about 7° are formed at the outcrop points of full edge dislocations, while the etch pits with the inclination angle of about 4° are associated with 45° mixed dislocations. It has been found that the dislocation structure of diamonds grown at 1900 °C is completely determined by the seed crystals structure and the dislocation density is 105 cm− 2. The dislocation density in the diamond crystals grown at 1800 °C increases by two or three orders of magnitude due to nucleation of dislocations at the seed-overgrown layer interface and in the overgrown layer. The high dislocation density leads to the mosaic structure of crystals and misorientation of single blocks, up to 1°. Local ring clusters of edge dislocations were found to be the dominant source of growth layers on the {100} faces of diamond.

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalDiamond and Related Materials
Volume70
DOIs
Publication statusPublished - 1 Nov 2016

Keywords

  • Dislocations
  • Etching
  • High pressure and high temperature
  • Synthetic diamond
  • X-ray topography

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