ClK edge SEXAFS of the Pd(111)-(√3 × √3) R30°-Cl surface reveals a Pd-Cl bond length 2.39 angstrom. Two previously unreported structures of chlorine on Pd(111) are identified, the (4 × 4) and a highly complicated surface with chlorine coverages of θ = 0.57 and θ ≤ 0.24, respectively, if the (√3 × √3) R30° surface is assumed to be θ = 0.33. The (4 × 4) structure is discussed in terms of a close packed hexagonal overlayer of chlorine on an unreconstructed metal surface and as a surface compound of palladium and chlorine. The highly complicated structure appears to comprise crystallites or islands of a palladium/chlorine compound and once formed is stable over a wide range of nominal chlorine coverages.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry