THICK-FILMS OF THE T1-BASED SUPERCONDUCTOR FABRICATED VIA THE SOL-GELTECHNIQUE

Superconducting thick films of Tl-based cuprate were grown via the sol -gel technique with a two-step method: deposition of a Tl-free precurs or film followed by Tl-vapor annealing. A zero resistance superconduct ing transition temperature (T-c) of 120 K on polycrystalline MgO subst rates for Tl-1223 films and of 124 K on (100) LaAlO3 substrates and po lycrystalline MgO substrates for Tl-2223 films was obtained. The intra granular critical current density at 5 K of these films is greater tha n 106 A/cm(2) for Tl-1223 and Tl-2223. The microstructure of these fil ms was examined with X-ray diffraction and scanning electron microscop y. (C) 1997 Elsevier Science B.V.