Angular Dependence of the Upper Critical Field of Bi sub (2.2) Sr sub 2 Ca sub (0.8) Cu sub 2 O sub (8+delta).

We have measured the electricity resistivity of Bi sub (2.2) Sr sub 2 Ca (0.8) Cu sub 2 O sub (8+delta) in the vicinity of T sub c for various angles between the [CuO sub 2 ] sub (inf) double-layers of the crystal and the magnetic field. Defining T sub c at the transition midpoints, we have measured values for -dK sup || sub (c2) /dT = 45 T/K and -dH 1 over (c2) /dT =0.75 T/K for the magnetic field parallel and perpendicular to the [CuO sub 2 ] sub (inf) planes, respectivity. This results in an anisotropy of a factor 60. The numerical results are sensitive to the definition of T sub c and higher values for the anisotropy cannot be excluded The results are compared with the anisotropic three-dimensional Ginzburg-Landau theory.