PROCESSING OF THICK-FILM ELECTRODEPOSITED THALLIUM OXIDE SUPERCONDUCTORS

Thick-film Tl-Ba-Ca-Cu-O superconductors (TBCCO) were synthesized on Ag foil and ceramic substrates using an electrodeposition process. The influence of Ag, initial stoichiometry, and reaction conditions on the phase development of TBCCO films were studied. Films deposited and reacted with no additional thallium source showed 1223 as the major phase, whereas films reacted using a two-zone thallation process showed 2223 as the primary phase formation. The TBCCO samples electrodeposited on Ag foil and annealed using the two-zone thallation process showed a critical current density of 3.2 x 10(4) A/cm2 at 76 K in zero field. The highest critical current density for films reacted without any additional thallium source was near 10(4) A/cm2 at 76 K in zero field.