Superconducting properties and electrical resistivities of NbN thin films have been studied as a function of sputtering parameters, film structure, and composition. A good correlation exists between superconducting Tc's and film structure and composition regardless of the sputtering conditions used to achieve this structure. The most important parameters affecting Tc are lattice parameter, crystal structure, island structure, and impurity content. Substrate temperature, Ar/N2 ratio, and impurity content are the principal sputtering parameters affecting film structure, and thus Tc.

Electroactive conducting copolymers of aniline and 4,4‘-diaminodiphenyl sulfone (DDS) were prepared electrochemically. The cyclic voltammetric studies were carried out with different feed concentration of DDS on a glassy carbon electrode surface. The voltammograms exhibited different behavior for different concentrations of DDS. The effect of scan rate and pH on the electroactive copolymer film was studied. The copolymer showed good adherence on the glassy carbon electrode surface and gave a response up to pH 7.0. Spectroelectrochemical analysis of copolymer film was carried out on an indium−tin oxide plate, and it showed multicolor electrochromic behavior when the applied potential was changed. The color of the copolymer was changed from neutral yellow (427 nm) to green (777 nm) and to blue (600 nm) at the concentration of 0.3 M aniline and 0.1 M DDS in 0.1 H2SO4 medium. When the DDS concentration changed to 0.5 M, the spectra exhibited the color change from neutral yellow (417 nm) to dark green (723 nm) and to dark blue (650 nm). The copolymer film was characterized by Fourier transform IR spectral data, and the surface morphology was studied using SEM analysis.

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