Microstructural development and superconducting properties of BaO2-added Bi2Sr2CaCu2O8+x

Investigations on the effects of Ba additions in Bi-2212 superconductors ar e focussed on compositional, microstructural, and magnetization studies, In previous studies, we showed that BaO2 reacts with Bi-2212 to form second p hases. Zero-field and in-field transport properties in Ag-clad BaO2 added B i-2212 tapes had been improved at 4.2 K [1]-[3]. SEM micrographs, pole figures, and transport critical currents versus magne tic held orientation suggest that BaO2 has a strong influence on the micros tructural properties. Magnetization studies revealed that BaO2 does not aff ect the pinning properties of optimally added Bi-2212, To estimate the pote ntial of BaO2 additions in creating possible pinning sites, TEM investigati ons were carried out focussing on sub-micrometer inclusions and growth defe cts in the superconducting phase.