DIMENSIONAL CROSSOVER IN Bi1.8Pb0.4Sr2Ca2Cu3Oy TEXTURED THICK FILM

The temperature dependence of resistance of C -axis oriented Bi (2223) thick film from 300 K to 100 K at 0 T (zero magnetic field) were measured. By choosing T c in different ways, such as R/Rn=0.9, 0.5, 0.1, 0.01 and 0.001, they are shown that the different results could be obtained. The data were described in terms of the classic theory of thermodynamic fluctuations. Two crossover from 2D to 3D and 1D to 2D was observed very close to the critical temperature T c when T c only was defined as zero-resistance temperature. The zero-temperature coherence length was estimated.