Effect of dopant mixture on structural, optical and electron spin resonance properties of polyvinyl alcohol

Pure polyvinyl alcohol (PVA) and PVA/(x)AgNO3(15−x)MnCl2 films, where x=0.0%, 1%, 5%, 7.5%, 10%, 14% and 15%, were prepared by casting technique. The prepared films were studied by differential thermal analysis, X-ray diffraction (XRD), spectral (UV-Vis-IR spectroscopy), DC conductivity and electron spin resonance (ESR). Thermal stability of the prepared films was decreased for doped films. XRD and spectral studies revealed that the structural and chemical characterizations of PVA are strongly affected by mixed fillers. The electric conduction data were interpreted on the basis of an intrachain one-dimensional interpolaron hopping model. The calculated values of the charge carriers hopping distance were in the range 2-6 nm. ESR spectra revealed that (i) aggregated forms of Mn2+ ions were formed at higher concentration and isolated forms at lower concentration and (ii) silver clusters were formed at x=15wt%. The filling level dependence of ESR parameters was discussed.