Fabrication and properties of DC-sputtered Tl-1223 superconducting thin films

A multi-step deposition and post annealing scheme has been developed for preparing nearly single phase, c-axis oriented TlBa/sub 2/Ca/sub 2/Cu/sub 3/O/sub 9/ (Tl-1223) superconducting thin films by dc-sputtering. The effects of the compensates used during post annealing on final phase formation suggest the crucial role played by thermodynamic conditions and further validates the viability of the present process scheme. In particular, films obtained by the present process have shown, for the first time in this system, a critical current density (J/sub c/) above 10/sup 6/ A/cm/sup 2/ at 77 K with a zero-resistance transition temperature (T/sub c0/) above 110 K. The results are attributed to the improvement of film morphology, specifically a decreased density of weak-links.<
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