Investigation of the ion dynamics by a particular excitation due to the stoichiometric imbalances on BiFeO3 ceramics

In this work, bismuth ferrite ceramics have been synthesized with various stoichiometric imbalances by the pressure-less sintering technique. UV–Vis spectroscopy and scanning electron microscopy show that both the band gap and the grain morphology of the ceramics are comparable to the stoichiometric imbalances. More necessarily, excess iron in the stoichiometry shows new charge carrier dynamics with the existence of completely new crystalline biferroic Bi1.2Fe0.8O3+δ ceramics. This means the iron ion valence fluctuation is well tailored by modifying iron contents. The conductivity study explains that two discrete forms of Johnscher’s power law and Super-linear power law types of conductivity mechanism can be induced by the change of stoichiometry. Obtained outcomes illustrate that stoichiometric imbalances play a major role in ion dynamics, leading to identifying a new path to engineer the properties of bismuth ferrite ceramics.