Magnetoconductance of Bi1.6Pb0.4Sr2Ca2Cu3Ox bulk superconductor in the fluctuation region

The temperature dependencies of the magnetoresistance of Bi1.6Pb0.4Sr2Ca2Cu3Ox bulk superconductor were measured within the transition from normal to the superconducting state. The critical temperature of the sample was found to be Tc50% = 107.1 K. The thermal fluctuations were studied using the following formula of conductance: Δσ=Kε−λ where ε = (T − Tc)/Tc, λ is the critical exponent and K is a constant. The critical exponents in the transition region were determined and their magnetic field dependencies were analysed. The crossovers from 1D to 3D and from 3D to 1D dimensional fluctuations were found within the regions of transition from the normal to the superconducting state.