Effect of Bi2O3 Addition on the Single-Crystal BiSrCaCuO Whisker Growth

Bi-2212 superconducting whiskers have been fabricated by annealing a melt-quenched precursor using suitable heat-treatment cycles for Bi3+xSr2Ca2Cu3O8+δ where x=1 and 2. Approximately 1–3 mm long whiskers were fabricated for x=1 and x=2 and their physical, electrical and magnetic properties were investigated. Crystallization activation energies of the materials were calculated according to Kissinger and Augis–Bennet method using the DTA data. Microstructural changes from glass to heat-treated glass-ceramic materials at different temperatures were investigated with SEM, EDX and XRD analyses. It was observed that the structure of the whiskers has high c-axis oriented single-crystalline Bi-2212 phase. The whiskers fabricated for x=1 and 2 showed very smooth surface without cracks and dislocations. Tc of the whiskers for x=1 and 2 were obtained to be 83.2 K and 79.8 K respectively. The change of magnetization with applied magnetic fields (M–H) was investigated at three different temperatures, 10, 20 and 40 K, and Jc mag was determined using the Bean model.