Relaxation and conduction mechanism of PVA: BYZT polymer composites by impedance spectroscopy

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.