Role of WO3 nanoparticles in electrical and dielectric properties of BaTiO3–SrTiO3 ceramics.

(BaTiO₃–SrTiO₃)/(WO₃)_x ceramics with x = 0 up to 5% were synthesized using solid-state reaction via high-energy ballf milling technique. Various characterization techniques were used including X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier transform-infrared spectroscopy (FT-IR), and UV–visible diffuse reflectance (DR) spectrophotometer. Structural analysis via XRD indicates the formation of two separate phases of SrTiO₃ (STO) and BaTiO₃ (BTO) having both cubic structures. The presence of BaWO₄ as impurity was detected for higher concentration. SEM observations show a reduction in the average grains size with increasing WO₃ addition. In comparison with free-added ceramic, the optical band gap energy (E_g) shows a slight increase with WO₃ addition. Contextual investigations on the electrical and dielectric properties of various WO₃ added to BTO–STO ceramics have been used to evaluate conductivity (σ ), dielectric constant and loss ( ε r ′ and ε r ″ ), and dissipation factor ( t a n δ ) against both frequency and dc bias voltages. Generally, both σ and ε r ″ correspond to the tendency of the power law to frequency. However, dc bias has been noticed to be lesser affecting the conduction mechanisms, which has a small variation for various WO₃ addition ratios. In addition, the dissipation factor was found to be highly dependent on both the addition ratio and the frequency as well as dc bias applied. [ABSTRACT FROM AUTHOR]