Structural phase transition of gold under uniaxial, tensile, and triaxial stresses: An ab initio study


Durandurdu M.

PHYSICAL REVIEW B, cilt.76, sa.2, 2007 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 76 Konu: 2
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1103/physrevb.76.024102
  • Dergi Adı: PHYSICAL REVIEW B

Özet

The behavior of gold crystal under uniaxial, tensile, and three different triaxial stresses is studied using an ab initio constant pressure technique within a generalized gradient approximation. Gold undergoes a phase transformation from the face-centered-cubic structure (fcc) to a body-centered-tetragonal (bct) structure having the space group of I4/mmm with the application of uniaxial stress, while it transforms to a face-centered-tetragonal (fct) phase within I4/mmm symmetry under uniaxial tensile loading. Further uniaxial compression of the bct phase results in a symmetry change from I4/mmm to P-1 at high stresses and ultimately structural failure around 200.0 GPa. For the case of triaxial stresses, gold also converts into a bct state. The critical stress for the fcc-to-bct transformation increases as the ratio of the triaxial stress increases. Both fct and bct phases are elastically unstable.