Extrinsic mechanism for giant dielectric response in Ba0.70Sr0.30(Fe0.5Nb0.5)O3 ceramic

To obtain the high dielectric constant, the effect of sintering process on the electrical properties of Ba0.70Sr0.30(Fe0.5Nb0.5)O3 ceramics were investigated. X-ray diffraction pattern of the samples at room temperature shows a monoclinic structure. Microstructure analysis shows well-grown and dense microstructure in all the samples. We found giant dielectric constant (∼3.59 × 105) with low dielectric loss (∼0.49) at room temperature for 2 hr sintered sample at 1250 °C. The extrinsic phenomena like interfacial polarization due to space charge accumulation at grain boundaries are discussed