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This study deals with the effects of various filling levels of a mixture of two transition compounds [(X)AgNO 3 (10 Ϫ X)MnCl 2 ] on the structural, electrical, and magnetic properties of atactic polystyrene (PS) films. X-ray diffraction (XRD) scans showed two main peaks for unfilled PS films. Crystalline peaks were unexpectedly detected with the filling and could be correlated to the formation of clusters. The IR transmission spectra revealed characteristic PS peaks. Certain IR peaks could be taken as evidence for the formation of polaron and bipolaron bound states in the polymeric matrix. The direct-current (DC) electrical conduction measurements suggested that the conduction mechanism could be attributed to phonon-assisted charge carrier hopping according to the interpolaron hopping model. The DC magnetic susceptibility results at 90 -235 K obeyed the Curie-Weiss law. The negative values of the paramagnetic Curie temperature ( p ) indicated the possibility of an antiferromagnetic exchange interaction, whereas the positive values of p suggested a ferromagnetic exchange interaction at low temperatures. An electron spin resonance (ESR) spectrum at X ϭ 0% revealed a broad Lorentzian signal. This suggested the presence of aggregated Mn 2ϩ and was confirmation of cluster formation found in XRD studies. On the other hand, ESR spectra at higher values of X depicted hyperfine structures characterized by the six unresolved lines of the manganese nucleus, indicating the existence of isolated Mn 2ϩ .