Emergence of state at Fermi level due to the formation of In-Sn heterodimers on Si(100)-2 x 1

• Published in: Physical review. B, Condensed matter and materials physics Vol. 88; no. 20
• Main Authors: Sobotik, P, Setvin, M, Zimmermann, P, Kocan, P, Ost'adal, I, Mutombo, P, Ondracek, M, Jelinek, P
• Format: Journal Article
• Language: English
• Published: 15-11-2013
• Subjects: Atomic structure; Codeposition; Condensed matter; Dimers; Fermi level; Fermi surfaces; Formations; Scanning tunneling microscopy
• ISSN: 1098-0121; 1550-235X

Structure and electronic properties of one-dimensional bimetallic In-Sn chains formed by codeposition on a Si(100)-2x1 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 x 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.