Impedance Spectroscopy Study of Bi1.34Fe0.66Nb1.34O6.35 Ceramics

The bismuth-based pyrochlore, Bi1.34Fe0.66Nb1.34O6.35, was prepared by the sol–gel method and synthesized at low temperature. The phase structure and the morphology were studied by x-ray diffraction and scanning electron microscopy. Even with treatments performed at low temperature, the obtained powders showed high crystallinity and nanosized grains. To investigate the dielectric performance, the impedance spectroscopy technique was used in the frequency range of 102-106 Hz, in function of the temperature (200-330 K). The prepared samples presented two temperature-dependent relaxation processes, with the corresponding activation energies being calculated by fitting the experimental data to the Arrhenius model.