Josephson effects in misaligned Tl-2212 films

We have measured Josephson RSJ-like static current-voltage characteristics in 2-mu m-wide bridges patterned in the [cos 20 degrees 0 sin 20 degrees] direction in 200 degrees misaligned thin films of Tl2Ba2CaCu2O8 grown on vicinal LaAlO3 substrates. The temperature dependence of the critical current of the bridge is well-described by Josephson SIS tunnelling between two BCS superconductors, with IcRn equal to 26 mV at 4.4 K. Conversely, the current-voltage characteristics of bridges patterned in the orthogonal [0 1 0] direction in the same films show flux-flow behaviour. This, coupled with the insensitivity of the inter-plane critical current to a small magnetic field, strongly suggests that the Josephson behaviour we have observed is due to intrinsic Josephson coupling between adjacent copper oxide planes, and not to extrinsic inter-grain coupling. (C) 1999 Elsevier Science B.V. All rights reserved.