Cation-anion mixed-dimer structure of Al-induced (2 × 4) reconstruction on InAs(001)

► We studied the structure of Al-induced (2 × 4) reconstruction of InAs(001). ► The (2 × 4)-Al surface has mixed In-As dimers with the Al atoms being incorporated into the subsurface layers. ► Heating of the (2 × 4)-Al surface promotes the Al diffusion into deeper layers, forming the In-rich (4 × 2) reconstruction.