Synthesis of Cobalt-Doped Bi 12 NiO 19 : Structural, Morphological, Dielectric and Magnetic Properties

The influence of cobalt doping on bismuth nickelate (Bi12NiO19) synthesized by sol–gel method has been investigated. The X-ray powder diffraction analysis proves that bismuth nickelate possesses cubic perovskite structure, and the same is retained even after Co doping. The average crystallite sizes were found to be in the range of 42–60 nm as estimated by Scherrer’s formula. The morphology of the samples analyzed by scanning electron microscopy reveals irregular-shaped structures of the samples. However, incorporation of Co has led to a significant morphological transformation. The dielectric properties were found to be consistent with the Koop’s phenomenological theory. Nyquist plots exhibit only one incomplete and distorted semicircle for all the samples specifying that the relaxation process deviates from the ideal Debye-type behavior. Magnetization measurements carried out using vibrating sample magnetometry (VSM) revealed paramagnetic behavior of the investigated samples. The results obtained from the impedance analysis give a true picture of the electrical behavior of the sample. The cobalt-doped bismuth nickelate ceramics have good prospects in scientific and industrial applications in the fields of sensors and memory devices.