Frequency dependent dielectric, modulus, impedance and AC conductivity study of Poly Vinyl Alcohol with 25 vol.% of Yttrium modified Barium Zirconium Titanate ceramic have been investigated. The single phase Yttrium modified Barium Zirconium Titanate ceramics have been synthesized by conventional solid state route. The relaxation mechanism of dielectric and modulus study is due to the segmental motion of polymer chain along with the dipole orientation of ceramic in the polymer composite. The Nyquist plot of impedance shows two semicircles, which represents the bulk and interfacial effect of polymer composites. The activation energy decreases with incorporation of higher Yttrium modified Barium Zirconium Titanate ceramics in the polymer matrix due to the even distribution of ceramic in the polymer composite. The different activation energy obtained from conduction and relaxation of the composite indicates that various mechanisms are involved in the conduction and relaxation process.

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In this work, Ba(Zr 0.25 Ti 0.75)O 3 ceramic was prepared by solid-state reaction. This material was characterized by x-ray diffraction and Fourier transform Raman spectroscopy. The temperature dependent dielectric properties were investigated in the frequency range from 1 kHz to 1 MHz. The dielectric measurements indicated a diffuse phase transition. The broadening of the dielectric permittivity in the frequency range as well as its shifting at higher temperatures indicated a relaxor-like behaviour for this material. The diffusivity and the relaxation strength were estimated using the modified Curie-Weiss law. The optical properties were analysed by ultraviolet-visible (UV-vis) absorption spectroscopy and photoluminescence (PL) measurements at room temperature. The UV-vis spectrum indicated that the Ba(Zr 0.25 Ti 0.75)O 3 ceramic has an optical band gap of 2.98 eV. A blue PL emission was observed for this compound when excited with 350 nm wavelength. The polarity as well as the PL property of this material was attributed to the presence of polar [TiO 6 ] distorted clusters into a globally cubic matrix.

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