Chemical and phase compositions of multilayer nanoperiodic $a$-SiO$_{x}$/ZrO$_{2}$ structures subjected to high-temperature annealing

The chemical and the phase compositions of multilayer nanoperiodic SiO$_{x}$/ZrO$_{2}$ structures prepared by vacuum evaporation from separated sources and subjected to high-temperature annealing have been studied by X-ray photoelectron spectroscopy with a layer-by-layer etching. It is found that, under deposition conditions used, the silicon suboxide layers had the stoichiometric coefficient $x\sim$1.8 and the zirconium-containing layers were the stoichiometric zirconium dioxide. It was found, using X-ray photoelectron spectroscopy, that annealing of the multilayer structures at 1000$^\circ$C leads to mutual diffusion of the components and chemical interaction between ZrO$_2$ and SiO$_{x}$ with predominant formation of zirconium silicate at heteroboundaries of the structures. The SiO$_{x}$ layers of the annealed nanostructures contained $\sim$5 at % elemental silicon as a result of the phase separation and the formation of fine silicon nanocrystals.