Evidence for improvement of critical current by Ag in YBaCuO-Ag thick films

The evidence is reported for enhancement of critical current density Jc in YBa2Cu3O7−δ thick films with the addition of Ag, which is correlated with improvements in structural properties. An improvement of 50% in Jc (up to ∼500 A/cm2 at T=4.2 K) was obtained in films made from YBCO+60wt % Ag powder, fabricated by the spin-on technique on (100) SrTiO3, which is correlated with improvements in structure. The resulting films are 10 μm thick, uniform, partially textured, and show good adherence. The critical temperature Tc is improved by the addition of Ag, and a reduction in the density of microcracks and in the amount of secondary phases in the sintered films was observed. Normal-state resistivity is reduced by almost three orders of magnitude, making these films potentially useful for electronic applications in interconnects and novel hybrid circuits.