Structural phase transition of germanium under uniaxial stress: An ab initio study

Durandurdu M.

PHYSICAL REVIEW B, vol.71, no.5, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 71 Issue: 5
  • Publication Date: 2005
  • Doi Number: 10.1103/physrevb.71.054112
  • Journal Name: PHYSICAL REVIEW B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Abdullah Gül University Affiliated: No

Abstract

An ab initio-constant pressure technique is applied to study the pressure-induced phase transition of germanium under uniaxial and hydrostatic stresses. The method successfully reproduces a first order phase transition from the diamond structure to a beta-Sn structure with the application of hydrostatic pressure. The simulations reveal that the uniaxially compressed germanium also undergoes similar phase transition via an intermediate state having a space group of I4(1)/amd. The transition pressure is significantly lowered for the uniaxial case, and the physical origin of which is associated with bond bending. The computed Poisson ratio of germanium agrees with experiments.