UNIAXIAL INCOMMENSURATE PHASES AT THE AU(111) ELECTRODE

The structure of the Au(111) electrode has been investigated using sur face X-ray scattering (SXS) in a variety of electrolytes. Although the underlying gold layers have hexagonal symmetry, the top most gold lay er forms a rectangular, uniaxial incommensurate (p x square-root 3) st ructure in the absence of specific adsorption. The (p x square-root 3) structure is also observed for bismuth and iodine adlayers, where p c ontinuously changes with potential (electrocompressibility).