FABRICATION, PROCESSING AND PROPERTIES OF TL-1223 CONDUCTORS

Fabrication of Tl-1223 conductors in two geometries is reported, Powder-in-tube (PIT) tapes were fabricated using aerosol generated precursor powders mixed with Tl2O3. Effect of processing variables such as temperature, time and uniaxial pressure were studied, Under optimum processing conditions the tapes have sharp transitions (widths similar to 1K) and zero-field J(c) similar to 0.9x10(4)A/cm(2) at 77K. However the taper lack any detectable grain orientation texture and are severely weak-linked, On the other hand, thick films (3-30 mu m) of Tl-1223 on Ag made using a variety of precursor deposition techniques followed by thallination in a two-zone flow reactor, show significantly reduced weak-link behavior and high zero-field J(c)'s (>10(4)A/cm(2)), It is found that these films are c-axis aligned (rocking curve FWHM similar to 3-11 degrees) and also possess varying degrees of Local in-plane texture, Microstructural development in these thick films is found to be similar to that observed previously for films on polycrystalline YSZ, Such thick films present a working model of a practical Tl-1223 conductor.