Synthesis of Bi2223 phase via PbO addition to the BSCCO(2234) system
In this study, PbO addition to the Bi2234 system was found to help in the formation of the Bi2223 phase. The resistance vs temperature (R-T) curves showed that the Tc increases with increasing PbO content indicating that the high-Tc phase stabilizes. The Tc for the pure sample is as high as 87K while the Tc for x=0.1 and x=0.3 is found at 89K and 106K, respectively. This study also showed that Bi2223 phase can be formed by sintering the samples for 24 hours at 840°C and for 48 hours at 850°C. The highest volume fraction of Bi2223 of 76.3% was attained for x=0.3 where the lowest volume fraction of 8.1% for Bi2212 was also obtained. The PbO enhanced the diffusion of the excess calcium and copper unit from the Bi2234 into the Bi2212 phase exhausting it for the formation of the Bi2223 phase as shown in the volume fractions obtained from the x-ray diffraction (XRD) spectra.