FLUCTUATION PHENOMENA IN EXCESS CONDUCTIVITY AND MAGNETIZATION OF SINGLE-CRYSTAL BI2SR2CACU2O8+Y

We present an analysis of the measured excess conductivity which resul ts from the fluctuation of the superconducting order parameter of a Bi 2Sr2CaCu2O8+y single crystal and found it was fit best by the two-dime nsional Aslamazov-Larkin theory. The magnetoconductivity and magnetiza tion studies are in good agreement with the two-dimensional (2D) scali ng behavior in the framework of Lawrence-Doniach model revealing the 2 D nature of the fluctuation near the mean-field transition temperature in the presence of a field.