Dielectric and impedance spectroscopic investigation of the Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 ceramic system

Polycrystalline Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 ceramics were processed via a mixed-oxide solid state sintering route at 1500 °C in air for 6 h. X-ray diffraction and scanning electron microscopy were used for phase and microstructural analyses of the Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 ceramics. The magnitude of relative permittivity (εr) was measured as 247 and tan δ as 0.008 at 1 kHz around the room temperature. Complex impedance spectroscopy (CIS) analysis was used to understand the electronic microstructure of the Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 ceramics. The magnitude of total resistance (RT) was observed to decrease with increasing temperature, which confirmed a negative temperature coefficient of resistance (NTCR) for the Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 ceramics. The Cole-Cole plot showed only one semicircle for the sintered sample, which confirmed the grain boundary contribution to the conduction mechanism. A non-Debye type of relaxation behavior was observed in the Ba0.3Sr0.7Ti0.873Zr0.097Mn0.03O3 sintered sample.