INTERFACIAL STRUCTURE OF IODINE ELECTRODEPOSITED ON AU(111) - STUDIES BY LEED AND IN-SITU STM

Iodine adlayers formed on Au(111) in aqueous KI solution have been studied by ex situ Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and in situ scanning tunneling microscopy (STM). The LEED patterns are described as c(p X root 3R - 30 degrees) where p decreases continuously with increasing emersion potential. By in situ STM, a series of rotated hexagonal structures was observed at positive potentials in addition to the c(p X root 3R - 30 degrees) structures. This rotated hexagonal adlattice was also compressed with increasing electrode potential. These results in general confirm the phenomenon of electrocompression of the iodine adlayer on Au(111) observed by in situ surface X-ray scattering.