A quantitative structural model, based on x-ray diffraction, is provided to analyze quadruple-period atomic ordering along  in a GaAs0.87Sb0.13 alloy grown on a (001) GaAs substrate by molecular beam epitaxy. To minimize the local strain energy derived by a valence force field (VFF) model for the alloy, atomic displacements were deduced and incorporated in our model. Calculation of the scattering pattern based on the model agrees well with experiment. We propose that this ordering originates from a (2×4) surface reconstruction and the difference in properties of the atomic species.
Physical Review B
- Pub Date:
- January 2001
- Structure of clean surfaces;
- X-ray diffraction and scattering;
- Structural modeling: serial-addition models computer simulation;
- III-V semiconductors