Properties of Tl-1223 superconducting thick films fabricated from precursor inks using a thallium vapor transport process

Using a two-zone thallium vapor transport furnace and a thick film ink process, we have successfully made superconducting films 10 to 50 /spl mu/m thick on a variety of substrates. Ba/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ and Bi/sub 0.22/Sr/sub 1.6/Ba/sub 0.4/Ca/sub 2/Cu/sub 3/O/sub x/ precursor films with and without Ag additions were made by mixing powders in an organic vehicle, painting a substrate and burning the vehicle off. Films were converted to the superconducting phase by passing an O/sub 2/ carrier gas over a Tl/sub 2/O/sub 3/ source and then the sample. TBCCO 1223 films generally form over a narrow sample temperature range near 860/spl deg/C, whereas TBSBCCO films form 1213, 1223 or a mixture of these phases depending on sample annealing temperature and O/sub 2/ partial pressure. TBCCO T/sub c/'s average 104 K with zero-field J/sub c/ (77 K) /spl ap/3500 A/cm/sup 2/ while TBSBCCO T/sub c/'s are higher at 110 K with J/sub c//spl ap/6800 A/cm2. Both compounds show weak-link behavior in a magnetic field.<>