STUDY ON ABNORMAL PHENOMENON ABOUT ENHANCED ELECTRICAL CONDUCTIVITY OF Bi1-xBaxFeO3 CERAMICS

In order to investigate the effects of Ba doping BiFeO3 on multiferroic properties, Bi1-xBaxFeO3(0≤x≤1)(BaxBFO) ceramics were fabricated via rapid solid phase sintering method, and material's structures and electrical properties were investigated. The phase transitions from rhombohedral to pseudo-cubic (x = 10%) and then to tetragonal (x = 40%) were confirmed by X-ray diffraction investigation. Although the electrical conductivity of BaxBFO (x = 10%, 20% and 30%) ceramics was low, which is a similar trend to previous reports, an abnormal enhancement of electrical conductance was observed in BaxBFO (x = 1%, 3% and 5%) ceramics. Such as, the electrical conductivity of Ba0.03BFO is calculated to be ~106 Ω⋅cm that is five orders of magnitude higher than that of the BiFeO3. This has been discussed and ascribed to more percent of oxygen vacancies and Fe2+ ions in BaxBFO ceramics, as confirmed by X-ray photoelectron spectroscopy investigation.