YBaCuO and TlBaCaCuO Superconductor Thin Films via an Electrodeposition Process

Thin-film superconductors of YBaCuO (YBCO) and TIBaCaCuO (TBCCO) were fabricated via an electrodeposition process. The YBCO superconductor precursor thin films were deposited at potentials ranging from-2.5 to-4 V vs. an Ag/AgNO₃ reference electrode. The YBCO films were deposited under both constant and pulsed-potential conditions. The post annealed YBCO films showed zero resistance of approximately 74 K on Ni, 78 K on MgO, and 91 K on ZrO₂ substrates. The best critical current densities obtained for the YBCO films at 4 K and zero magnetic field and their respective substrates are as follows: 4000 A/cm² on [100] ZrO₂, 3960 A/cm² on [100] MgO (constant potential), 5160 A/cm² on [100] MgO (pulsed potential), 500 A/cm² on a Ni strip, 325 A/cm² on a Ni wire, and 500 A/cm² on a Ag wire. The precursors of the superconducting TBCCO films were codeposited at a constant potential of-4 V and also under pulsed potential conditions. The post-annealed TBCCO films showed zero resistance at about 102 K on SrTiO₃ substrate. The critical current density at 76 K of a TBCCO film deposited at constant potential on a silver coated SrTiO₃ substrate was 20, 000 A/cm² in zero magnetic field and 5, 000 A/cm² in a 10 kOe field parallel to the film plane. The critical current density of pulsed potential deposited TBCCO film on SrTiO₃ was 56, 000 A/cm² at 76 K in zero field.