Structural determination of [ital p]2[ital mg](2[times]1)CO/Ni(110) with the use of angle-resolved photoemission extended fine structure

Journal Article · Thu Jul 15 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.1696· OSTI ID:6348216

Huang, Z; Hussain, Z; Huff, W T; Moler, E J ^[1]; Shirley, D A ^[2]

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1. Department of Chemistry, University of California, Berkeley, Berkeley, California 94720 (United States) Chemical Sciences Division, Mail Stop 2-300, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
2. Departments of Chemistry and Physics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

The technique of angle-resolved photoemission extended fine structure has been used to study the chemisorption geometry of the dense [ital p]2[ital mg](2[times]1)CO/Ni(110) overlayer at low temperatures. Photoemission intensities from the carbon 1[ital s] core level were measured in three directions as a function of photoelectron kinetic energy in the range 60--400 eV. Using multiple-scattering spherical-wave (MSSW) modeling, we confirmed that the CO molecules form a zigzag-chain geometry on the Ni(110) surface at saturation coverage, with adjacent CO molecules along the [1[bar 1]0] direction displaced alternatively in opposite directions towards the [001] and the [00[bar 1]] azimuths. We further determined that the CO molecules are adsorbed on the short-bridge sites, the tilt angle for the direction linking the carbon atom and the center of the nickel bridge being 16[degree][plus minus]2[degree] from the surface normal. The carbon-nickel interatomic distance was determined to be 1.94[plus minus]0.02 A. The first- to second-layer spacing of nickel is 1.27[plus minus]0.04 A, up from 1.10 A for the clean Ni(110) surface, but close to the 1.25-A Ni interlayer spacing in the bulk. Using the findings of earlier studies of this system, the C-O bond length and tilt angle were varied within small ranges (1.10--1.20 A and 15[degree]--23[degree], respectively) in our MSSW simulations. At 1.16 A and 19[degree] the best agreement between the experimental data and the theoretical simulations was achieved. The above results yield an O-O distance of 2.95 A for the two nearest CO molecules, close to twice the van der Waals radius ([similar to]1.5 A) for oxygen.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6348216
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:3; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
CRYSTALS
ELEMENTS
EMISSION
ENERGY RANGE
EV RANGE
EV RANGE 10-100
EV RANGE 100-1000
FINE STRUCTURE
METALS
MONOCRYSTALS
NICKEL
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
SECONDARY EMISSION
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TRANSITION ELEMENTS