Effects of epitaxial films of nanometric thickness on the X-ray photoelectron diffraction intensities from substrates

The effects on the X-ray photoelectron diffraction intensities from the substrate produced by epitaxial NiO(0 0 1) films of various thickness deposited on Ag(0 0 1) were investigated. The variations in the Ag XPD curves induced by the NiO films can be explained in terms of multiple scattering of the electrons emitted by the substrate atoms along the close-packed rows of the overlayer. Intensity minima in the XPD curves from the substrate in correspondence to intensity maxima in the XPD curves from the overlayer are observed when the thin film is commensurate with the substrate. For films of suitable thickness, the analysis of XPD curves from the substrate allows one to get information about the structure of the film and of the film–substrate interface.