Ordering in GaAs1−xSbx grown by molecular beam epitaxy

Ordering in (100) GaAs1–x Sbx epilayers grown by molecular beam epitaxy has been studied by transmission electron microscopy. Diffraction patterns taken from plan-view and cross-sectional samples of epilayers reveal a unique evolution of the ordering with the growth temperature, showing the formation of a short range order at lower temperatures and a long range order at higher temperatures. A distinct anisotropy of the formation of ordered structures between [011] and [01̄1] axes is observed from all epilayers investigated. Based on the analysis of the growth conditions, it is suggested that the anisotropy of the ordering is caused by the surface atomic structure of the growing epilayers.