Formation of a very high-density amorphous phase of carbon and its crystallization into a simple cubic structure at high pressure


DURANDURDU M.

COMPUTATIONAL MATERIALS SCIENCE, vol.200, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 200
  • Publication Date: 2021
  • Doi Number: 10.1016/j.commatsci.2021.110822
  • Title of Journal : COMPUTATIONAL MATERIALS SCIENCE
  • Keywords: Amorphous, Phase transformation, Polyamorphism, DLC, TRANSITIONS

Abstract

We report a direct computational evidence of a two-step transformation sequence for tetrahedral amorphous carbon (ta-C) with increasing pressure. First, ta-C gradually transforms into a very high-density amorphous phase (VHDA) phase. Second, the VDHA phase converts into a simple cubic (SC) crystal. The structural defects formed during the high-pressure treatment play important roles for the formation and stabilization of the SC structure, rather than favorable the SC4 crystal. These phase transformations are reversible.