AC Susceptibility and Electrical Properties of BiFeO3 Nanoparticles Added Bi1.6Pb0.4Sr2Ca2Cu3O10 Superconductor

The effect of bismuth ferrite (BiFeO 3 ) nanoparticles (~ 20 nm) on Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O 10 (Bi-2223) superconductor was studied. Bi-2223 powders with starting formula Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O 10 (BiFeO 3 ) x for x = 0–0.20 wt.% were prepared using the co-precipitation method. The temperature dependent electrical resistance measurements showed the highest superconducting transition temperature for the x = 0.10 wt. % sample ( T c-onset = 118 K, T c-zero = 106 K). The highest transport critical current density, J ct at 40 K was shown by the x = 0.02 wt. % sample (21.93 A cm −2 ). The peak temperature of imaginary part of susceptibility, T p was much higher compared with the non-added sample, indicating BiFeO 3 nanoparticles enhanced the flux pinning energy and intergranular coupling. The addition of a small amount of BiFeO 3 nanoparticles (0.02–0.04% wt.%) increased the transport critical current density while further additions (0.06–0.20 wt.%) improved the superconducting transition temperatures. BiFeO 3 nanoparticles slightly suppressed the formation of the Bi-2223 phase, but it increased the transport critical current density by more than eleven times demonstrating BFO could act as effective pinning centres and enhanced connectivity between grains. This work showed that BiFeO 3 was better than other nanoparticles such as Ni 0.5 Zn 0.5 Fe 2 O 4 , Cr 2 O 3 , NiFe 2 O 4 , MgO, ZnO and Co 3 O 4 in improving the transition temperatures and critical current density of the Bi-2223 phase superconductor.