Surface Structure Determination of C(2×2) N2/Ni(100) and Low and Intermediate Coverages of Co/Cu(111) by Angle-Resolved Photoemission Fine Structure (Arpefs) Using Synchrotron Radiation

Abstract

AbstractWe have determined the adsorption site and interlayer spacings of c(2×2) N2/Ni(100),(√3 × √3)R30° and (1.5 × 1.5)R18° CO adsorbed on Cu(111), using ARPEFS and a full Multiple-Scattering, Spherical Wave (MSSW) calculation program. The nitrogen molecule stands upright at an atop site, with a N-Ni bond length of 2.25(1) Å, a N-N bond length of 1.10(7) Å, and a first layer Ni-Ni spacing of 1.76(4) Å. The C-Cu bond length is 1.91 (1) Å in the (√3 × √3)R30° phase and 1.91(2) Å in the (1.5 × 1.5)R18° phase. The first layer Cu-Cu spacing is 2.07(3) Å in the (√3 × √3)R30° phase. The first layer Cu-Cu spacing in the (1.5 × 1.5)R18° phase is 2.01(4) Å, a contraction of 3 % from the clean metal value of 2.07 Å.