X-ray diffuse scattering study of vacancy nanoclusters in homoepitaxial Ag(001) films

The analysis of x-ray diffuse scattering measurements on Ag homoepitaxial films is presented. The experiments, which establish that a low concentration of large vacancy clusters can be incorporated into noble metals during homoepitaxial growth, were performed on 100 monolayer films of Ag deposited on Ag(001) at low temperature. The diffuse scattering of this film was measured, in situ, near several in-plane Bragg positions in grazing-incidence geometry. Because of the large dilatation from the vacancy clusters, the usual approximations of Huang and Stokes-Wilson scattering cannot be made and it is shown that numerical integration of the diffuse scattering equations leads to good agreement between the data and a point-defect scattering model.