Azimuthal- and Polar-Angle-Dependent Surface Extended X-Ray—Absorption Fine-Structure Study: (2×1)O on Cu(110)

Abstract

A low-symmetry twofold bridge site of (2\ifmmode\times\else\texttimes\fi{}1) oxygen on Cu(110) allows the determination of the azimuthal dependence of the surface extended x-ray---absorption fine structure. For normal incidence and $\stackrel{\ensuremath{\rightarrow}}{\mathrm{E}}$ parallel to the [100] and [110] directions we determine the nearest- and second-nearest-neighbor distances to be 1.84(2) and 2.00(5) \AA{}, respectively. We show that the atomic oxygen is occupying the low-symmetry twofold bridge site in the [100] direction 0.35 \AA{} above the first Cu layer.