Accession Number : ADA317314

Title :   Se Addlattices formed on Au(100), Studies by LEED, AES, STM and Electrochemistry.

Descriptive Note : Technical rept. 1 Jun 95-15 Oct 96,

Corporate Author : GEORGIA UNIV ATHENS DEPT OF CHEMISTRY

Personal Author(s) : Huang, Baoming M. ; Lister, Tedd E. ; Stickney, John L.

PDF Url : ADA317314

Report Date : 15 OCT 1996

Pagination or Media Count : 47

Abstract : Ordered selenium atomic layers have been formed electrochemically on Au(100) at a series of coverages. Cyclic voltammetry and coulometry were used to study the deposition process, and to determine the corresponding coverages of a number of Se structures. Structures, with Se coverages of 1/4, 1/3, 1/2, and 8/9 monolayers (ML), were identified using ultra high vacuum - electrochemical (UHV-EC) techniques as well as scanning tunneling microscopy (STM). The corresponding unit cells of those structures were: p(2x2), (2X 10), c(2X2), and mostly (3X 10), composed of close-packed Se8 rings. Pit formation, associated with formation of the densely packed Se8 ring structure, was observed, and is reminiscent of pits observed in self assembly monolayers (SAMs) of alkane thiols on Au surfaces. The pits disappeared as the structure composed of Se rings, was converted to lower coverage structures, such as the 1/4 ML p(2X2), via anodic stripping. Se atomic layers were formed electro-chemically in three ways: direct reduction from a HSeO3 solution, anodic stripping of previously formed bulk Se, or cathodic stripping of previously formed bulk Se. All three methods resulted in equivalent atomic layer structures on the Au(100) surface, but with some variation in the homogeneity and distribution of articular structures.

Descriptors :   *CRYSTAL LATTICES, *GOLD, *SELENIUM, SCANNING, EMISSION, SPECTROSCOPY, LAYERS, CELLS, TUNNELING(ELECTRONICS), ELECTRONIC SCANNERS, STRUCTURES, ELECTROCHEMISTRY, CYCLES, ALKANES, REDUCTION, ELECTRON MICROSCOPY, DEPOSITION, LOW ENERGY, ASSEMBLY, RINGS, ELECTRON DIFFRACTION, VOLTAMMETRY, ATOMIC PROPERTIES, ULTRAHIGH VACUUM, ATOMIC STRUCTURE, THIOLS, COULOMETERS.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE