Identification of first and second layer aluminum atoms in dilute AlGaAs using cross-sectional scanning tunneling microscopy

Abstract
Cross‐sectional scanning tunneling microscopy is used to study dilute AlxGa1−xAs with x=0.05 to investigate the bonding configurations within this ternary alloy. Atomically resolved scanning tunneling microscopy images combined with symmetry considerations provide the assignment of first and second layer aluminum atoms. The Al–Al pair distribution function based on the experimental data is compared with the theoretical pair distribution function of a random alloy. While there exists a qualitative agreement, small deviations from the ideal random distribution are also found.