摘要
Bi<sub>2</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>y</sub>-Ag<sub>x</sub>, Bi<sub>1.7</sub>Pb<sub>0.3</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>y</sub>-Ag<sub>x</sub> and Bi<sub>1.7</sub>Pb<sub>0.3</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3.2</sub>O<sub>y</sub>-Ag<sub>x</sub> were prepared by the solid state reaction. Analytical reagents AgNO<sub>3</sub>, PbO, Bi<sub>2</sub>O<sub>3</sub>, SrCO<sub>3</sub>, CaCO<sub>3</sub> and CuO were used as starting materials. Appropriate quantities of the starting materials were mixed, ground and fired at 800°C for 12 h, reground, pressed and sintered for
