Effect of Yttrium Doping on Magneto-transport Properties of Bi(Pb)-2212 Superconductors

An analysis of the temperature dependence of resistivity results under magnetic fields (0-7 T) is presented for yttrium doped Bi1.6Pb0.4Sr2Ca1-x Y (x) Cu2O8+delta and Bi1.6Pb0.4Sr2-x Y (x) CaCu2O8+delta (x=0 and 0.075) superconductors. The experimental methodology is mainly based on DC measurements in the range temperature of 10-300 K. The activation energy (U (0)) is calculated using the Arrhenius law (rho(T)=rho (0)exp(-U (0)/K (B) T)). The irreversibility fields (mu (0) H (irr)) and upper critical fields (mu (0) H (c2)) are extracted using the previously proposed methods. The study shows that the highest values of these parameters are seen for the doped sample at the Ca site, suggesting that the flux lines are effectively pinned in this compound when compared to the others. The calculated physical parameters such penetration depth (lambda(0)) and coherence length (xi(0)) are also in good agreement with values previously published for this phase. The upper critical field has a maximum value when the hole concentration per CuO2 unit (P) is around 0.179.