Measurements of the excess conductivity above the transition temperature on selected, high-quality, superconducting epitaxial films of the 2:2:1:2-phase Bi-Sr-Ca-Cu-O (BSCCO), obtained by liquid-phase epitaxy, are reported. The data confirm the two-dimensional nature of the thermodynamical fluctuations in BSCCO compounds in a wide range of temperature above ${\mathit{T}}_{\mathit{c}}$ and very good agreement is found with an extended version of the Aslamazov-Larkin theory [L. Reggiani, R. Vaglio, and A. A. Varlamov, Phys. Rev. B 44, 9541 (1991)].

• Received 2 March 1992

DOI:https://doi.org/10.1103/PhysRevB.46.14919