Structure and electronic properties of one-dimensional bimetallic In-Sn chains formed by codeposition on a Si(100)-2$\times$1 surface are studied experimentally by means of scanning tunneling microscopy (STM) and scanning tunneling spectroscopy and theoretically using density-functional theory. The codeposition of In with a small amount of Sn allows separation of various In-Sn structures and their identification in empty-state STM images. A 16$\times$2 supercell is employed to model an indium atomic chain in which one or two Sn atoms are embedded. This atomic model is used to identify unambiguously various In-Sn structures observed experimentally. At low Sn:In ratio the codeposition results in strongly preferential formation of isolated heterogeneous In-Sn dimers. The In-Sn dimer induces tilting of the neighboring homogeneous In-In dimer accompanied with a charge transfer. Consequently a localized state at Fermi level appears. These results contribute to a discussion on possible transport of electric charge along one-dimensional atomic chains of metals.

• Received 20 May 2013

DOI:https://doi.org/10.1103/PhysRevB.88.205406