Improved microstructure and flux pinning properties of Gd-substituted (Bi,Pb)-2212 superconductor sintered between 846 and 860 °C

The influence of sintering temperature on microstructural and superconducting properties of Gd-substituted (Bi,Pb)-2212 superconductor was investigated. It is found that the microstructure of the system can be tailored and refined so as to yield the best superconducting properties in terms of critical current density (JC) and flux pinning by heat treating at a temperature in the range 846–860 °C. The samples sintered at 858 °C show the maximum self-field JC of 31,960 kA m− 2 and those sintered at 846 °C show the maximum flux pinning force [FP = 1698 kN m− 3] as against 1860 kA m− 2 and 16 kN m− 3, respectively for the undoped sample sintered at its optimum sintering temperature. The changes in microstructure followed by very high enhancement of JC, JC–B characteristics and FP due to Gd-substitution within a small temperature range, is of great scientific and technological significance.