Atomic structure of two-dimensional binary surface alloys: Si(111)-√21×√21 superstructure

• Published in: Surface science Vol. 606; no. 11-12; pp. 919 - 923
• Main Authors: Fukaya, Y., Matsuda, I., Hashimoto, M., Kubo, K., Hirahara, T., Yamazaki, S., Choi, W.H., Yeom, H.W., Hasegawa, S., Kawasuso, A., Ichimiya, A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-06-2012; Elsevier
• Subjects: Alloys; Atomic structure; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diffraction; Exact sciences and technology; Gold; Photoemission spectroscopy (PES); Physics; Reflection high-energy positron diffraction (RHEPD); Silicon; Silver; Spectra; Stoichiometry; Superstructures; Surface structure; Two-dimensional alloys; Gold; Silver; Reflection high-energy positron diffraction (RHEPD); Two-dimensional alloys; Silicon; Photoemission spectroscopy (PES); Surface structure; Two-dimensional systems; Photoelectron spectroscopy; Binary alloys; Transition elements; Superstructure; Atomic structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2012.02.006

The atomic structures of Au and Ag co-adsorption-induced √21×√21 superstructure on a Si(111) surface, i.e., (Si(111)-√21×√21-(Au, Ag)), where the Si(111)-5×2-Au surface is used as a substrate, have been investigated using reflection high-energy positron diffraction (RHEPD) and photoemission spectroscopy. From core-level spectra, we determined the chemical environments of Ag and Au atoms present in the Si(111)-√21×√21-(Au, Ag) surface. From the rocking curve and pattern analyses of RHEPD, we found that the atomic coordinates of the Au and Ag atoms were approximately the same as those of the Au and Ag atoms in other Si(111)-√21×√21 surfaces with different stoichiometries. On the basis of the core-level and RHEPD results, we revealed the atomic structure of the Si(111)-√21×√21-(Au, Ag) surface.
► Two-dimensional Ag–Au alloy phases on Si(111) surface have been investigated. ► Chemical environments of Ag and Au atoms were revealed by core-level spectra. ► Atomic coordinates were determined by reflection high-energy positron diffraction. ► Atomic structures for the alloys with different stoichiometries are almost identical.