This work reports on the change in the silversilver interatomic distance dAgAg as a function of the coordination number for silver clusters supported on MgO(1 0 0) surfaces. Interatomic distances were determined by means of X-ray absorption spectroscopy (XAS) at the silver K-edge. For coordination number lower than 7 (below an average thickness equivalent to 1 ML), dAgAg is contracted with respect to the bulk parameter and scales with cluster size. For coordination numbers ranging between 7 and 10 (between 1 and 3 ML), dAgAg increases above the bulk value and shows a tendency to match the MgO(1 0 0) substrate. It then relaxes back to the bulk distance. Coordination numbers found herein successfully compare those derived from a model based on grazing incidence small angle X-ray scattering measurements. At low coverage, the XAS data measured by the total electron yield method exhibits diffraction peaks which are consistent with the presence of structurally coherent islands on the MgO substrate.
Elastic strains in silver clusters supported on MgO(100)
Colonna S;
2003
Abstract
This work reports on the change in the silversilver interatomic distance dAgAg as a function of the coordination number for silver clusters supported on MgO(1 0 0) surfaces. Interatomic distances were determined by means of X-ray absorption spectroscopy (XAS) at the silver K-edge. For coordination number lower than 7 (below an average thickness equivalent to 1 ML), dAgAg is contracted with respect to the bulk parameter and scales with cluster size. For coordination numbers ranging between 7 and 10 (between 1 and 3 ML), dAgAg increases above the bulk value and shows a tendency to match the MgO(1 0 0) substrate. It then relaxes back to the bulk distance. Coordination numbers found herein successfully compare those derived from a model based on grazing incidence small angle X-ray scattering measurements. At low coverage, the XAS data measured by the total electron yield method exhibits diffraction peaks which are consistent with the presence of structurally coherent islands on the MgO substrate.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
