The high-temperature superconducting material Bi2Sr2CaCu2Ox (2212) was synthesized by reaction of oxides and carbonates. Several stoichiometries and a range of temperatures and oxygen partial pressures were investigated for the production of pure 2212. The reaction sequence to form Bi2Sr2CaCu2Ox was found to consist of initial formation of Bi compounds, their subsequent reaction to form the Bi2Sr2CuOx phase and CaCu oxides, and a slow reaction to form the Bi2Sr2CaCu2Ox phase. The best powder was made from a Bi:Sr:Ca:Cu composition equal to 2.0:1.7:1.0:2.0. The optimum heat treatment was found to consist of initial heating to about 725 °C in flowing oxygen at a reduced total pressure of 5 x 102 Pa, followed by brief heating in air to about 885 °C, and, finally heating in air at 842 °C for 2 to 3 days.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering