Increasing Electrical Resistivity of P-Type BiFeO[sub.3] Ceramics by Hydrogen Peroxide-Assisted Hydrothermal Synthesis

Bismuth ferrite (BiFeO[sub.3] , BFO) is still widely investigated both because of the great diversity of its possible applications and from the perspective of intrinsic defect engineering in the perovskite structure. Defect control in BiFeO[sub.3] semiconductors could provide a key technology for overcoming undesirable limitations, namely, a strong leakage current, which is attributed to the presence of oxygen vacancies (VO) and Bi vacancies (VBi). Our study proposes a hydrothermal method for the reduction of the concentration of VBi during the ceramic synthesis of BiFeO[sub.3] .Using hydrogen peroxide (H[sub.2] O[sub.2] ) as part of the medium, p-type BiFeO[sub.3] ceramics characterized by their low conductivity were obtained. Hydrogen peroxide acted as the electron donor in the perovskite structure, controlling VBi in the BiFeO[sub.3] semiconductor, which caused the dielectric constant and loss to decrease along with the electrical resistivity. The reduction of Bi vacancies highlighted by a FT-IR and Mott—Schottky analysis has an expected contribution to the dielectric characteristic. A decrease in the dielectric constant (with approximately 40%) and loss (3 times) and an increase of the electrical resistivity (by 3 times) was achieved by the hydrogen peroxide-assisted hydrothermal synthesized BFO ceramics, as compared with the hydrothermal synthesized BFOs.