White Laue and powder diffraction studies to reveal mechanisms of HCP-to-BCC phase transformation in single crystals of Mg under high pressure.

Academic Article


  • Mechanisms of hexagonal close-packed (HCP) to body-centered cubic (BCC) phase transformation in Mg single crystals are observed using a combination of polychromatic beam Laue diffraction and monochromatic beam powder diffraction techniques under quasi-hydrostatic pressures of up to 58 ± 2 GPa at ambient temperature. Although experiments were performed with both He and Ne pressure media, crystals inevitably undergo plastic deformation upon loading to 40-44 GPa. The plasticity is accommodated by dislocation glide causing local misorientations of up to 1°-2°. The selected crystals are tracked by mapping Laue diffraction spots up to the onset of the HCP to BCC transformation, which is determined to be at a pressure of 56.6 ± 2 GPa. Intensity of the Laue reflections from HCP crystals rapidly decrease but no reflections from crystalline BCC phase are observed with a further increase of pressure. Nevertheless, the powder diffraction shows the formation of 110 BCC peak at 56.6 GPa. The peak intensity increases at 59.7 GPa. Upon the full transformation, a powder-like BCC aggregate is formed revealing the destructive nature of the HCP to BCC transformation in single crystals of Mg.
  • Authors

  • Vasilev, Evgenii
  • Popov, Dmitry
  • Somayazulu, Maddury
  • Velisavljevic, Nenad
  • Knezevic, Marko
  • Publication Date

  • February 7, 2023
  • Published In

  • Scientific Reports  Journal
  • Digital Object Identifier (doi)

    Start Page

  • 2173
  • Volume

  • 13
  • Issue

  • 1