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

• Published in: Journal of materials science. Materials in electronics Vol. 31; no. 10; pp. 7786 - 7797
• Main Authors: Slimani, Y., Unal, B., Almessiere, M. A., Hannachi, E., Yasin, Ghulam, Baykal, A., Ercan, I.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2020; Springer Nature B.V
• Subjects: Barium titanates; Bias; Ceramics; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Dielectric properties; Dissipation factor; Electrical resistivity; Energy gap; Fourier transforms; Infrared analysis; Infrared spectroscopy; Materials Science; Nanoparticles; Optical and Electronic Materials; Scanning electron microscopy; Strontium titanates; Structural analysis; Tungsten oxides; X ray powder diffraction; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-03317-7

(BaTiO 3 –SrTiO 3 )/(WO 3 ) 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 SrTiO 3 (STO) and BaTiO 3 (BTO) having both cubic structures. The presence of BaWO 4 as impurity was detected for higher concentration. SEM observations show a reduction in the average grains size with increasing WO 3 addition. In comparison with free-added ceramic, the optical band gap energy ( E g ) shows a slight increase with WO 3 addition. Contextual investigations on the electrical and dielectric properties of various WO 3 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 WO 3 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.