The effect of nanocomposite formation of NiWO4 with tin phthalocyanine on the structural, optical and electrical properties of NiWO4

NiWO₄/SnPc nanocomposite samples were synthesized by the solvent evaporation method. The structural and optical properties were investigated using various characterization techniques. From the XRD analysis, the modification of the geometrical parameters of NiWO₄ by the composite formation was identified. Raman analysis confirmed the nanocomposite formation as the Raman spectra of the composite samples had the characteristic vibrations of SnPc. From the optical studies, both direct and indirect band gaps of the composite samples were analysed. The optical band gap was found to be tuned by the composite formation. It also changed the luminescence properties of the nickel tungstate samples. The colour of emission of the composite samples varied significantly. The electrical properties of pure and composite samples were analysed with the help of dielectric permittivity, dissipation factor and conductivity. By the formation of NiWO₄/SnPc nanocomposites, the dielectric constant of NiWO₄ was found to be increased. Nyquist plots along with the equivalent circuits were used to analyse the relaxation and conduction mechanism of pure NiWO₄ and nanocomposite samples. All the samples showed a non-Debye type relaxation process. Composite samples showed small values of complex impedance which might be due to the additional charge carriers formed by the incorporation of SnPc into the NiWO₄ lattice. The formation of nanocomposite with SnPc changed the structural, optical and electrical properties of NiWO₄ samples. The enhanced dielectric constant and conductivity of the nanocomposites made them applicable for microelectronic applications.