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

Tl-1223 films have been fabricated using spray pyrolysis on silver and zirconia substrates. We have investigated the effect of a Tl-2212/TlF source powder and observed a significant increase in melting and, consequently, a reduction of around 20/spl deg/C in the optimum reaction temperature and increased grain growth. We have found that the effect of the fluorine is greatest in the presence of silver. We have also observed that films grown on polycrystalline silver tape have several preferred in-plane orientations.