Quantitative structure determination of GaAs(0Â 0Â 1) under typical MBE conditions using synchrotron X-ray diffraction

Surface structures of GaAs(0 0 1) under molecular beam epitaxy conditions are described on the basis of in situ X-ray diffraction measurements. Exploiting the high-intensity, high angular resolution and element sensitivity of synchrotron X-rays, we revealed the details of the most frequently used surfaces including several phases of (2×4) and c(4×4).