Amorphous SiO/SiO2 multilayers were studied using grazing-incidence small-angle X-ray scattering (GISAXS). Such SiO/SiO2 superlattices were prepared by alternately magnetron sputtering of 3 nm thin films of SiO and 3 nm of SiO2 (10 layers each) on Si (100) substrate. Rotation of the Si substrate during evaporation ensures the homogeneity of the films over the whole substrate. After evaporation the samples were annealed at 1050 degrees C for 2 h in vacuum or in air. The analysis of the 2D GISAXS patient has shown that Si nanocrystals are formed in the annealed samples. Using a Guinier approximation, the inter-nanocrystal distance (10.5 nm) and radius of gyration (2.3 nm) have been obtained for the samples annealed in vacuum. Samples annealed in air have shown similar peak values which were however, much wider distributed. (c) 2006 Elsevier B.V. All rights reserved.