Аннотация:Composite materials comprised of a ceramic matrix with metal-containing nanoparticles were prepared by sintering iron (II) oxalate and polycarbosilane. The chemical composition of the material can be controlled by a sintering process. Sintering in inert atmosphere leads to reduction of the sample and metal iron formation (a-Fe, carbide). Formation of iron oxides requires calcination procedure in series (argon and air) for removing by products. The air-sintering materials consist mainly of oxide phases, but also contain metal iron. The prepared samples were characterized by the SEM, TEM, XRD and EMR techniques and the Mössbauer spectroscopy. It was shown unique behavior that iron containing particles after calcination in air decreased from 5-30 nm to 2-5 nm due to interaction with matrix under air atmosphere.