Magnetic field for the onset of resistivity: Angular dependence and temperature-induced dimensional crossover in Bi-Sr-Ca-Cu-O

The temperature-induced crossover from a two-dimensional (2D) to 3D behavior found in 2:2:1:2 Bi-Sr-Ca-Cu-O is studied by means of a large set of measurements of the magnetic field ${\mathit{H}}^{\mathrm{*}}$ for the onset of dissipation. Some interesting features of the angular dependence near the crossover temperature are found; in particular, the ${\mathit{H}}^{\mathrm{*}}$ values perpendicular to a-b planes lie on the irreversibility line. The angular behavior of ${\mathit{H}}^{\mathrm{*}}$ is analogous to that of the upper critical field in conventional layered superconductors. A tentative explanation is given.