2D TO 3D CROSSOVER IN BI-SR-CA-CU-O - COMPARISON WITH SYNTHETIC MULTILAYERED SUPERCONDUCTORS

We show that in a highly c-oriented 2:2:1:2 Bi-Sr-Ca-Cu-O film the angular-dependent magnetic field H* at the onset of the resistivity behaves experimentally in a way completely analogous to the critical field found in synthetic multilayered superconductors. In particular, on varying the temperature, the field H* exhibits a crossover from a 2D to an anisotropic 3D behavior as a function of the angle-curly theta between the external magnetic field and the a-b plane