The effect of different dwell times at a constant pelletization pressure of 6 GPa on superconducting properties of Bi1.8Sr2Ca1.1Cu2.1Oy ceramics

Abstract

In this study, the physical and magnetic properties of Bi1.8Sr2Ca1.1Cu2.1Oy superconductors kept in different dwell times (1, 6, and 12 h) at a constant pelletization pressure of 6 GPa in the pressing step as prepared by standard solid-state reaction method are reported. The X-ray diffraction data shows that all samples have a tetragonal crystal structure with predominant Bi-2212. SEM micrographs for all samples predominately show plate-like grain structure, indicating the presence of Bi-2212 phase. Both Tc (onset) and Tc (offset) significantly increase with increasing dwell time. M–H measurements were performed at T = 10 and 25 K, respectively. In addition, Jc values of the samples were calculated from their magnetic hysteresis loops using the Bean’s model. It has been found that Jc in the samples including long dwell times under the pelletization pressure of 6 GPa improves.