SYNTHESIS AND PROPERTIES OF SR-FREE BI CUPRATE SUPERCONDUCTORS

Both the oxygen content and T-c(onset) of the Bi2Ca2.5(Ln, Ln(+))(0.5) Cu2Oy system monotonically increases as the mean ionic radius of (Ln, Ln(+)) increases. The structural modulations in all of the samples are almost commensurate with a period equal to 9b. In Bi2-xPbCa2.5Nd0.5Cu 2Oy, T-c(onset) decreases with increasing Pb concentration. In order t o investigate the effect of post annealing using a hot isostatic press (HIP), Bi2Ca2.5La0.25Pr0.25Cu2Oy was processed under different HIP co nditions. This result suggested that HIP annealing causes a phase chan ge from the 232 structure to the 221 structure.