Structural and impedance spectroscopic study of Zn-substituted Ba5CaTi2Nb8O30 tetragonal tungsten bronze ceramics

Zn-doped tungsten bronze compounds derived from Ba5CaTi2Nb8O30, with Ba5CaTi2−xZnxNb8O30 composition (x = 0; 0.04 and 0.08) were synthesized by the conventional solid-state reaction route. Both solubility of Zn in Ba5CaTi2Nb8O30 formation P4bm space group verified Rietveld method using X-ray diffraction data. The average crystallite size was order 0.08 µm according to Scherrer's formula. SEM micrographs ceramics showed high densification, low porosity, thus a homogeneous grain distribution different sizes over entire surface. range 1.3–1.6 µm. frequency-dependent electrical properties analyzed complex impedance spectroscopy. Different types studies such as Nyquist plot, real imaginary part impedance, conductivity, modulus formalism, charge carrier activation energy used explain microstructure-electrical relationships.