Tl-based films grown on silver tape substrates

The Tl-based superconductors belong to potential candidates for high-current and high-field applications. It is therefore of importance to prepare them in the shape of tapes and wires. It seems that silver tape is a very convenient material having suitable mechanical properties as well as chemical compatibility with superconducting films deposited and grown on top of them. In our case, Tl-based films were grown using a two-step procedure. First, the Ba-Ca-Cu precursors were deposited on a commercial silver tape from an aerosol, and then the precursors were thallinated in a closed crucible with a source of Tl-oxide in the form of a crude pellet. Results are reported on superconducting samples consisting so far of 2212, 2223 and 1223 phase mixtures. SEM observations reveal the growth of plate-like grains. Metallurgical processing of silver tape is underway to obtain a cubic texturized substrate which should help to improve transport properties of the grown films.