Effects of ion doping at different sites on electrical properties of multiferroic BiFeO3ceramics

Pure, La 3+ doped at A site, V 5+ doped at B site, and La 3+ and V 5+ co-doped multiferroic BiFeO 3 ceramics: BiFeO 3 (BFO), Bi 0.85 La 0.15 FeO 3 (BLF), BiFe 0.97 V 0.03 O 3 (BFV), Bi 0.85 La 0.15 Fe 0.97 V 0.03 O 3 (BLFV), etc were successfully prepared by a rapid liquid sintering technique. X-ray diffraction indicated that these ceramics were of polycrystalline perovskite structures, accompanied with a tiny residual Bi 2 O 3 phase. It was found that, among these ceramics, BLFV ceramic exhibited the best electrical properties. The leakage current density of BLFV ceramic was only 2.1 × 10 −6 A cm −2 at 10 kV cm −1 , two and one orders of magnitude lower than those of the BLF and BFV ceramics, respectively. In the measuring frequency of 4 KHz–1 MHz, the dielectric constants and losses of this sample exhibited slight variation and the lowest loss tangent was 0.08. The sample had a relatively saturated ferroelectric hysteresis loop. These suggested that the co-doped BiFeO 3 ceramic by La 3+ and V 5+ at A and B sites showed advantages in application over the pure BFO, doped BLF and BFV ceramics, respectively.