Facile synthesis and characterizations of Co²⁺ doped Bi_0.8Ba_0.2FeO₃ nano-crystalline multiferroic ceramics

Barium doped BiFeO₃ and Cobalt doped Bi_0.8Ba_0.2FeO₃ (BBFO) nanocrystalline multiferroic ceramics were prepared by the sol-gel technique. Rhombohedral symmetry was observed throughout the compositions, and the effect of sintering temperature was observed on volume and grain size of BBFO at (400 °C–700 °C) using x-ray profiles. The final sintering temperature for Cobalt doped (BBFCO) was estimated by using thermal analysis. DC I-V (current-voltage) analysis was used to analyze the leakage current density and conduction mechanism of ceramics. The temperature-dependent electrical resistivity measurements confirmed the metallic behaviour of Co²⁺ doped BBFO multiferroics at low temperatures, and transition temperature T_MI was also found to be Cobalt concentration-dependent. The dielectric response, electrical impedance, and Modulus of the material were measured in the frequency range 100Hz to 2MHz at room temperature. Trends or occurrences may be attributed to oxygen vacancies arise due to doping content. (paper)