Nickel substitution effect on superconducting properties of Bi-2212 ceramics

The effects of Ni substitution on the properties of high temperature superconductor Bi2Sr2−xNixCa1Cu2Oy were investigated. The samples were prepared by substituting Ni (x = 0.0-0.25) in different ratios by a conventional solid-state reaction method. It is observed that MR (remnant magnetization) enhances in sample N4 due to its better granular structure. Jc is experimentally calculated through dc magnetic-hysteresis loop measurements (M-H), employing the well known Bean's critical model. It was found that the grain size increases for sample N4 and consequently increases the critical current density values.