Electrochemical synthesis of different metal-conducting polymer composites and their modifications by gamma and heavy ion radiations
Abstract
The present work reports the two step electrochemical synthesis of processfor the fabrication of different metal conducting polymer composites (viz.Au-polyaniline, Au-polypyrrole and Ag-polypyrrole). Initially, conductingpolymers such as polyaniline and polypyrrole were electrochemicallysynthesized on different substrate using a chronopotentiometery techniquewith optimized process parameters. The synthesized conducting polymerfilms act as working electrode for the decoration of submicron metalparticles on the surface of conducting polymer films through acyclicvoltammetry (CV) technique. Later, these composite films wereirradiated with gamma and under high vacuum (~5×10-6 Torr) at roomtemperature with different heavy ion beams radiations at various fluencesranging. The composites are characterized by scanning electron microscopy(SEM), micro-Raman and X-ray diffraction spectroscopic techniques beforeand after irradiation. Raman studies revealed that structure of the filmsbecame disordered after irradiation, which was also observed in SEMimages. Detailed Raman and XRD spectroscopic analysis had been presentedand SEM investigations showed that the craters were formed in the filmswith increase of ion fluence. The present investigations explore theapplicability of irradiated composite films for sensor applications.
Metal-insulator transition and engineering of extended states in disordered systems beyond one dimension
Abstract
We shall discuss how to engineer wave function delocalization in disordered systemsmodeled by tight binding Hamiltonians in d > 1 dimensions. Exact analytical results willbe presented for the case of a two legged ladder network infinitely large along the x-axis,revealing how it can finally be used as a switching device. The results persist even whenthe ladder expands in the transverse direction, making a journey towards a real twodimensional system. The study gives rise to the possibility of designing disorderedpotentials that might work as band-pass filters for quantum waves, such as matter wavesin optical lattices.
