Gamma radiation induced modifications in Au-polypyrrole nanocomposites: Detailed Raman and X-ray studies

A facile electrochemical synthesis of Au-polypyrrole (Au-PPy) composite films has been reported. The synthesized composite films were irradiated with a 1.25 MeV Co-60 gamma radiation with doses ranging from 500 to 1500 kGy and the corresponding changes in structural properties of the composites were studied. The structural investigation of Au-PPy composite films were performed by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and micro-Raman spectroscopic techniques. XRD studies showed the variation in peak intensities after gamma irradiation. Different parameters like crystallite size, micro strain, dislocation density and distortion parameters were calculated from XRD spectra. Observed results indicate the formation of an ordered system in the irradiated composite films. SEM micrograph showed significant interactions between the Au-particles and PPy film after gamma irradiation. Raman spectra show an overall increase in peak intensity after gamma irradiation.