Transport properties of Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/ meander lines

We have measured the electrical transport properties of 10 cm long Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/ thin film meander lines in magnetic fields up to 18 T. The large resistance of the meander line effectively increased the electric field, or equivalently, resistivity sensitivity by two orders of magnitude. In moderate magnetic fields the critical current density is found to depend only on the component of the magnetic field normal to the ab planes owing to the highly anisotropic nature of the system. The resistivity versus temperature was measured as a function of magnetic field up to 18 T. The linear resistivity is found to vanish in a manner consistent with the occurrence of a second order phase transition. The critical exponent v(z-1) is virtually field independent with a value 5.3/spl plusmn/1 consistent with previous measurements of a three dimensional vortex glass transition in YBa/sub 2/CaCu/sub 3/O/sub 7/ and Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/. The critical regime is 10-15 K wide in agreement with values for Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/ at high magnetic field.<
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