THE ELECTROCHEMICAL-BEHAVIOR OF BI(PB) SRCACUO SUPERCONDUCTORS IN AQUEOUS-SOLUTIONS

Electrochemical behavior of Bi(Pb)SrCaCuO superconductors was studied by potentiodynamic scanning in different aqueous solutions with a conc entration of 0.1 M. The electrochemical stability, which is dependent on the passivation region and pH value of the aqueous solution, of the Bi2Sr2CaCu2Ox (2212) phase is superior in H2SO3(aq) and H3PO4(aq), wh ile that of the Bi2Sr2Ca2Cu3Oy (2223) phase is superior in NH4OH((aq)) , KCl(aq) and H2SO4(aq). Passivation was observed in H2SO4(aq) and H3P O4(aq) for both phases. These solutions are thus possible etchants in lithography for these superconductors. The phase on the etched surface of the 2212 or 2223 BiSrCaCuO superconductor remained unchanged after potentiodynamic study in KCl(aq) and H2SO3(aq).