X-ray scattering by nano-particles within granular thin films, investigation by grazing angle X-ray reflectometry

It is shown here that the observation of the phenomenon of like small angle scattering of X-rays in very thin heterogeneous films: can be made comparatively easily by using grazing angle reflectometry of X-rays. The feasibility was achieved with co-sputtered thin films of approximately 600 Angstrom thickness, made up by crystalline platinum clusters embedded in an amorphous alumina matrix. The experimental reflectivity profiles are simulated by the intensity superposition of two components: (i) the specular part caused by the usual interference phenomenon between the partial waves reflected from the air-film and film-substrate interfaces; and (ii) the like-small angle scattering part due to diffraction by platinum clusters. It is found that the shape of such clusters is spherical characterized by mean values of diameter [phi(c)] and inter-cluster distance [S-c] of the order 29 Angstrom and 45 Angstrom respectively with standard deviations sigma(phi) and sigma(s) of title order of 3 Angstrom. Such an observation of both the interference and diffraction phenomena indicates that the thin granular film exhibits both its continuous and heterogeneous aspects together.