Dissipation Of The Bi2.4-Xpbxsr2cacu2o8+Y Intrinsic Array Josephson Junctions

We have fabricated a small-sized mesa on the surface of the Bi2.4-xPbxSr2CaCu2O8+y single crystals and measured the temperature dependence of the out-of-plane resistivity in different magnetic Fields. The irreversibility line Hi,.,,(T) follows different law in different temperature regions. But as a whole, the higher doping level x is, the irreversibility line locates in a higher field. The field dependence of activation energy follows U-eff proportional to H-m, m increases when doping level x improves.