Variation of superconducting transition temperature and lattice parameters of Bi2Sr2CaCu2O8+δ after quenching under high pressure

Processes of the Bi-2212 phase formation and growth in multiphase Bi high-T c superconducting cuprates subjected to quenching under pressure (from temperatures as high as 1500°C and pressures up to 9 GPa) using various pressure-transmitting media were studied. As in the case of the Bi-2223 phase formation in quasi-single phase 2212 samples subjected to cold pressing, the measured dependencies of the superconducting transition temperatures and lattice parameters of the 2212 phase on the quenching conditions were used to assess the changes in its chemical composition depending on the quenching conditions. The data obtained can be used in optimizing processing conditions used in the fabrication of the 2212-containing materials.