Co nanocrystals in amorphous multilayers – a structure study

Abstract

The structure of magnetron-sputtered Co/SiO2multilayers has been investigated using grazing-incidence small-angle X-ray scattering, X-ray diffraction, transmission electron microscopy and ion scattering techniques. A theoretical description of diffuse X-ray scattering from three-dimensional self-assembled ensembles of nanoparticles is also presented. The data revealed that Co-rich nanoparticles self-organize in a three-dimensional lattice and a dependence of the lattice parameters as well as the mean particle size on the nominal layer thickness was observed. Originally amorphous Co-rich layers crystallize readily during deposition, creating both pure Co and Co oxide particles. The results presented are important for controlled production and reliable characterization of metallic nanoparticles in solid amorphous matrices, aiming to obtain a well ordered monodisperse ensemble of nanoparticles.