Impedance spectroscopic study of temperature and frequency dependent conduction behaviour of xBa(Zr0.2Ti0.8)O3-(1-x)(Ba0.7Ca0.3)TiO3, x=0.50, 0.55, 0.70, 0.85 ceramic

Here, we report on structural, impedance, modulus and conductivity analyses of xBa(Zr0.2Ti0.8)O3-(1-x) (Ba0.7Ca0.3)TiO3 (x = 0.50, 0.55, 0.70 and 0.85) polycrystalline ceramic prepared using conventional solid state reaction technique. The X-ray diffraction (XRD) pattern for all the synthesised polycrystalline samples confirmed the formation of pure perovskite phase. A slight variation in the lattice parameters were observed with varying concentration of x in BCZT ceramic. Composition dependence of average crystalline size and lattice strain of the synthesised samples were evaluated by Williamson-Hall plot. The samples near the Morphotropic phase boundary (MPB) were much strained with large crystallite size. The impedance spectroscopic study was done to evaluate the conduction behaviour of the BCZT samples with varying concentration of x in wide temperature and frequency range. All the samples were found to exhibit Negative temperature coefficient of resistance suggestive semiconducting nature of the synthesised samples. A comparative detail conduction behaviour with grain and grain boundary contribution is presented and discussed in detail.