Bi-induced (2 × 6), (2 × 8), and (2 × 4) reconstructions on the InAs(1 0 0) surface

Low-energy electron diffraction (LEED), scanning-tunneling microscopy (STM), and synchrotron-radiation photoemission results show that Bi induces (2 × 6), (2 × 8), and (2 × 4) reconstructions on the InAs(1 0 0) surface with decreasing Bi coverage. The α2-like structural model, established previously for the clean InAs(1 0 0)(2 × 4) surface, is proposed for Bi/InAs(1 0 0)(2 × 4), and two Bi 5d core-level components of this reconstruction are interpreted within the context of this model. For the Bi/InAs(1 0 0)(2 × 6) surface we propose a tentative model where two topmost atomic layers consist of Bi atoms. Some possible reasons why Bi forms chain-like (2 × 6) and (2 × 8) reconstructions, instead of the prototypical c(4 × 4) stabilized normally by As on III-As(1 0 0), are discussed.