Magnetoconductivity of Bi2Sr2Ca1−xYxCu2O8+δ in fluctuation regime

The magnetoconductivity of polycrystalline Bi2Sr2Ca1−xYxCu2O8+δ, x=0, 0.05 and 0.20 samples in the magnetic field of 4 T was measured. The excess conductivity has been analyzed in the light of Aronov–Hikami–Larkin and Bieri–Maki formalisms together with Thompson’s correction of the Zeeman term of both theories. The later theory was found within the clean limit to describe the data adequately and yielded the estimate for the phase braking time τφ≂1×10−13 s. The Maki–Thompson–Zeeman contribution (ΔσMTZ) in these samples is found to be negligible.