High-pressure phases of ZrO2: An ab initio constant-pressure study

Oezturk H., Durandurdu M.

PHYSICAL REVIEW B, vol.79, no.13, 2009 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 79 Issue: 13
  • Publication Date: 2009
  • Doi Number: 10.1103/physrevb.79.134111
  • Journal Name: PHYSICAL REVIEW B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Abdullah Gül University Affiliated: No

Abstract

The high-pressure behavior of ZrO2 is studied using an ab initio constant-pressure technique up to 140 GPa. Two high-pressure phases of ZrO2 are predicted through constant-pressure simulations. ZrO2 undergoes a first-order phase transformation from the baddeleyite structure to an orthorhombic structure with space group Pbcm at 35-40 GPa. The coordination number of Zr atoms unexpectedly changes from sevenfold to sixfold owing to this phase transformation. Further increase in pressure leads to another first-order phase transformation from the Pbcm structure to a tetragonal one with the space group P4/nmm at 70-80 GPa. In this structure, Zr atoms are ninefold coordinated. These phase transformations should occur around 11 and 38 GPa from enthalpy calculations, respectively.