Quadruple-period ordering along [110] in a GaAs0.87Sb0.13 alloy - art. no.033314

A quantitative structural model, based on x-ray diffraction, is provided to analyze quadruple-period atomic ordering along [110] in a GaAs0.87Sb0.13 a lloy grown on a (001) GaAs substrate by molecular beam epitaxy. To minimize the local strain energy derived by a valence force held (VFF) model for th e alloy, atomic displacements were deduced and incorporated in our model. C alculation of the scattering pattern based on the model agrees well with ex periment. We propose that this ordering originates from a (2X4) surface rec onstruction and the difference in properties of the atomic species.