Resistivity tensor of superconducting Bi sub 2 Sr sub (2.2) Ca sub (0.8) Cu sub 2 O sub 8 crystals.

A strongly anisotropic resistivity tensor was measured from the superconducting T sub c = 81K to 600K in crystals of the new high-T sub c superconductor having nominal composition Bi sub 2 Sr sub (2.2) Ca sub (0.8) Cu sub 2 O sub (8+x). In- plane components rho sub a >~ rho sub b are linear in T and imply two-dimensional metallic conduction within the Cu-O planes. The perpendicular component rho sub c ~ 1ohmcm is 10 sup 5 greater than rho sub a or rho sub b and 100 times greater than in the YBa sub 2 Cu sub 3 O sub 7 superconductor. Evidence for non-metallic T sup (-1) spinon transport between planes is revealed in the temperature dependence of the rho sub c / rho sub (ab) resistivity ratio. An alternate explanation that weak interplanar coupling may be caused by topological defects is also presented.