Patterned Y1Ba2Cu3Oy films on Y2BaCuO5 substrates by a surface diffusion process

A technique which combines the fabrication and the patterning of 10‐μm‐thick films of the high Tc superconducting Y1Ba2Cu3Oy directly on the Y2BaCuO5 ceramic substrates has been developed. The Ba3Cu5Oy(3BaCuO2+2CuO) powders were patterned on the substrate by silk‐screen printing and then heat treated at 930 °C for 3 h in an oxygen atmosphere. Measurements of resistivity and critical current density at 77 K for a patterned Y1Ba2Cu3Oy film with a 250‐μm width and 10‐μm thickness show zero resistivity at 88 K and 103 A/cm2, respectively. The microwave loss measured on the Y2BaCuO5 substrate is found to be negligibly low below 77 K.