Rapid Preparation of YBCO Coated Conductors Using Ag Tapes by Liquid Phase Epitaxy

We have succeeded in YBa2Cu3O7-d(YBCO) thick film growth on seeded single crystals of silver plates and on seeded cube-textured silver tapes by liquid phase epitaxy (LPE). In order to decrease the processing temperature far from the melting point of silver (941 °C in the ambient atmosphere), we use a novel solvent which is composed of BaO-CuO-BaF2-Ag. The typical processing temperature is about 860–900°C. The YBCO films formed on the seeded Ag(110) single crystalline substrates show very flat surface morphology and good in-plane orientation as well as good c-axis orientation perpendicular to the substrate surface. The good in-plane alignment of YBCO<100> // Ag<001> is also observed. These films show superconductivity at about 90K. The films formed on cube-textured tapes of Ag{100}<001> also show complete coverage and c-axis orientation. We have proved a possibility of fabricating long superconducting tapes using textured silver tapes by the LPE processing, which is superior to the conventional vapor phase deposition for the rapid and lower cost fabrication of thick films.