Annealing Effect on Resistivity of BiSrCaCu2Oy

The annealing effect on the resistivity and the critical temperature of BiSrCaCu2O y where the low temperature phase is predominant was examined. The resistivity becomes higher, as increasing the annealing temperature in N2 atmosphere and the sample annealed above 700°C did not show zero resistance from 20 K to 300 K. However, the resistivity and the critical temperature recover nearly the same value as the as-grown sample after annealing in O2 atmosphere.