HIGH-TC OF UNDOPED AND FLUORINE-DOPED YBA2CU3OY FILMS ON CERAMIC SUBSTRATES BY SCREEN PRINTING

Thick films of undoped and fluorine-doped YBa2Cu3Oy were screen printed on highly polished alumina, magnesia spinel, strontium titanate, and yttria-stabilized zirconia (YSZ) substrates. They were annealed at 1000-degrees-C and soaked in oxygen at 450-degrees-C followed by slow cooling to room temperature. The films were characterized by electrical resistivity measurements as a function of temperature and by X-ray diffraction. The films on YSZ showed the best characteristics with a T(c)(onset) of 91 K, T(c)(R = 0) of 88.2 K, and a transition width, DELTA-T(c)(10-90%), of almost-equal-to 1.7 K. The film adhesion, probably controlled by interdiffusion of cations between the film and the substrate, was good in all cases except on strontium titanate where the film completely detached from the substrate.