Structural phase transition of gold under uniaxial, tensile, and triaxial stresses: An ab initio study
PHYSICAL REVIEW B, cilt.76, sa.2, 2007 (SCI-Expanded)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 76 Sayı: 2
- Basım Tarihi: 2007
- Doi Numarası: 10.1103/physrevb.76.024102
- Dergi Adı: PHYSICAL REVIEW B
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Abdullah Gül Üniversitesi Adresli: Hayır
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.