Optimization of phase formation and microstructure in Tl-1223 thick films

Tl-1223 films have been fabricated using spray pyrolysis on silver and zirc onia substrates. We have investigated the effect of a Tl-2212/TlF source po wder and observed a significant increase in melting and, consequently, a re duction of around 20 degrees C in the optimum reaction temperature and incr eased grain growth. We have found that the effect of the fluorine is greate st in the presence of silver. We have also observed that films grown on pol ycrystalline silver tape have several preferred in-plane orientations.