Improvement of the superconducting properties of carbon addition on Bi1.6Pb0.4Sr2 Ca2Cu3O10+δ prepared through the two-step sintering process

The effects of the addition of carbon nanoparticles and nanotubes on the Bi1.6Pb0.4Sr2 Ca2Cu3O10+delta (BPSCCO) have been reported. BPSCCO samples were synthesized using the sol-gel method. BPSCCO with nominal composition was sintered at 840 degrees C for 30 h, then grounded and added an amount of carbon. Pure and carbon added BPSCCO were sintered at 840 degrees C for 30 hours. Resistivity measurements were carried out to determine the superconducting properties of the samples. We found that the addition of carbon nanoparticles and nanotubes increased the critical zero temperature (Tc-zero) of BPSCCO from 94.67 K to 97.8 K and 102.03 K for the pure BPSCCO, 0.05 wt% carbon nanoparticles added BPSCCO, and 0.2 wt% carbon nanotubes added BPSCCO, respectively. Based on the X-ray diffraction and SEM results, we can see that the main phase formed in the samples is dominated by the orthorhombic Bi-2212 phase structure, and the morphology typical of the BPSCCO superconductor which is a plate-like granular form has been observed in all samples.