An ab initio-based approach to phase diagram calculations for GaAs(001) surfaces

抄録

Surface phase diagram of GaAs(001) is systematically investigated by using our ab initio-based approach. The phase diagrams of the c(4 × 4) and (2 × 4) surfaces are clarified as functions of temperature and As pressure. The calculated results reveal that c(4 × 4)β and (2 × 4)γ surfaces are strongly affected by As-molecular species such as As₂ and As₄. The c(4 × 4)β surface consisting of As dimers disappears under As₄ because of small desorption energy of As dimers. The (2 × 4)γ surface appears only at high As pressure and low temperatures buried in the stable region of c(4 × 4)β under As₄. These results are compared with experimental results to check the versatility of our approach to the surface phase diagram calculations. [DOI: 10.1380/ejssnt.2005.488]