X-ray standing-wave study of monolayers of Sb on GaAs(110)

The x-ray standing-wave technique has been used to determine the geometrical structure of Sb on GaAs(110). Using the back reflection diffraction geometry from (220) and (400) planes, we find the average vertical distance of Sb atoms from the GaAs surface to be 2.27±{}0.05 {} in agreement with theoretical calculations for the epitaxial continued layer strucuture. Other models of buckled zigzag chains are found inconsistent with our results. Additionally, our data indicate less than 10% disorder in the Sb overlayer.