Nanostructured Fe/Fe-oxide systems with a chain morphology formed by interconnected metallic clusters were prepared by sputtering at very low substrate temperatures. The effect of the in situ controlled oxidation at low temperature leads to an effective decoupling of the particles forming the chains, which is attributed to a physical separation of particles through formation of a core-shell metal-oxide structure. In contrast, samples oxidized at room conditions exhibit features of strongly correlated particle systems, in which magnetic decoupling and stabilization can be explained within the framework of the random anisotropy model by considering the effect of the oxide phase. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559918]