The Study of Superconducting Precursors in Bi/Pb Superconductors Fabricated using the Shock Wave and Sun Technologies by the Torsion Oscillation Magnetometry

Abstract

The possibility of increasing the critical temperatures T_c of superconducting precursors in samples of Bi-Pb-Sr-Ca-Cu-O superconducting system fabricated using the hot shock wave consolidation technology (HSWC) and solar energy for melting and following superfast quenching of the melt was investigated by the vibrating torsional magnetometry method. By using the HSWC technology for the synthesis of samples in the range of pressures from P=5 GPa up to P=12 GPa. the critical temperature Tc of potential superconducting precursor transition to the superconducting state increased from  T_c  =107 K for starting sample to T_c =138 K. In the Bi-Pb-Sr-Ca-Cu-O  superconducting system samples, synthesized using solar energy for the melting and following superfast quenching of the melt, a superconducting precursor with  T_c  \(\approx\) 200 K was detected. The analysis of the nature of obtained dependences and their comparison with other available results associated with the processes in the vicinity of critical temperature T_c allows one to conclude that there are the high-temperature superconducting precursors with T_c \(\geq\) 240 K in samples of this system.