Structure of double row quantum wires in Au/Si(5 5 3)

• Published in: Surface science Vol. 581; no. 2; pp. 199 - 206
• Main Authors: Ghose, S.K., Robinson, I.K., Bennett, P.A., Himpsel, F.J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-05-2005; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Faceting; Gold; Physics; Self-assembly; Silicon; Surface structure; Vicinal single crystal surfaces; X-ray diffraction; Gold; Self-assembly; Vicinal single crystal surfaces; X-ray diffraction; Silicon; Faceting; Surface structure; Quantum wires; Vicinal surface; Monocrystals; Transition elements; XRD
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2005.02.053

We present a new structure for the quantum-wire surface Au/Si(5
5
3) obtained from three-dimensional X-ray diffraction measurements. We have found the structure has double row of gold, so the wires are two atoms thick. The diffraction pattern is 1
×
1 implying a simple (CTR-only) structure, but disorder is necessary in the model to get a good fit, in the form of a 50–50 splitting of the position of one of the gold sites. A 50% occupied Si adatom is also found, which is a common structural theme of Si(1
1
1) vicinal surfaces. Since there are insufficient available bonds for an adatom to reside in every unit cell, the Au splitting can be seen as a consequence of the alternating presence of the adatoms. No half order diffraction was observed, so any local order of these features must be assumed to be short-range.