Synthesis and superconducting properties of (Pb0.5Cd0.5)Sr2(Y0.5Ca0.5)Cu2O7

The effect of synthesis conditions on (Pb0.5Cd0.5)Sr-2(Y0.5Ca0.5)Cu2O7 has been investigated. For the (Pb,Cd)-1212 phase, quenching is not necessary. Quenching the (Pb,Cd)-1212 phase exclusively suppresses its superconductivity, although quenching is favorable for the (Pb,Cu)-1212 phase in removing the extra oxygen of the (Pb,Cu)O layers. On the other hand, annealing the (Pb,Cd)-1212 phase in flowing nitrogen leads to a phase decomposition from Pb-1212 phase to Pb-3212 phase. In this paper, we report the optimal synthesis condition for the (Pb,Cd)-1212 phase by annealing the (Pb,Cd)-1212 phase at 970 degrees C in O-2 for 2 h.