Paraconductivity in YBa2(Cu1−xNix)3O7–y and Bi2Sr2Ca1−xYxCu2O8+y

Abstract In the paraconductivity of Bi 2 Sr 2 Ca 1−x Y x Cu 2 O 8+y (x=0, 0.1, 0.3) we find the normal conductivity σ n (T) to play an important role. With Anderson-Zou expression for σ n (T) only, we find the excess conductivity to exhibit the cross over from 2D to 3D as the Tc is approached.