High argon and nitrogen gas pressure and low plasma power has been used to produce carbon nitride (CN x ) and nickel carbon nitride (Ni@CN x ) films by reactive dc magnetron sputtering. Under these conditions, the growth of the film occurs as a process of precipitation of clusters of sputtered material, rather than individual atoms. Scanning electron microscopy and high-resolution x-ray photoemission spectroscopy were used for structural characterization of CN x films on quartz substrates. The corresponding structural diagram determined by the substrate temperature and nitrogen concentration in the CN x film has been built. It includes four main nanostructures: graphite-like, fullerene-like, diamond-like and nano columnar. Production conditions of core/shell (nickel/carbon-nitride) nanocolumnar structures have been discussed.