New nanocomposite hybrid films of a well dispersed cerium disulphate Ce(SO(4))(2) nanoparticles into the polyvinylpyrrolidone (PVP) matrix were prepared by a casting technique. The nanostructural nature and complex formation were investigated using the transmission electron microscopy (TEM), the nuclear magnetic resonance (NMR), and the Infrared (IR) spectroscopy. The magnetic measurements at room temperature, using a vibrating sample magnetometer (VSM), and the obtained magnetic parameters revealed that the investigated nanocomposites belong to a category of magnetically soft materials that find widespread applications in contemporary fine technologies. Optical absorption spectra were measured in the ultraviolet (UV)visible region and the fundamental absorption edge E(a), the energy gap E(g) and width of the tail of localized states E(e) were evaluated and discussed in terms of the solid band theory. The monotonic increase of these optical parameters with the dopant concentration may be attributed to probable segregation effects occurring in the amorphous host matrix. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 2121-2129, 2011