PROPERTIES OF SPRAYED YSZ BUFFER LAYERS ON ALUMINA SUBSTRATES FOR YBCO THICK-FILMS

Yttria-stabilized-zirconia (YSZ) buffer layers on polycrystalline alum ina substrate were fabricated by spraying a suspension consisting of u ltrafine YSZ ponders. It was found that the spraying conditions such a s the flow rate of carrier gas and the aperture of spray nozzle had a great influence on the mechanical properties of the sprayed buffer lay ers and also on the J(c) values of YBCO thick films processed on these buffer layers. The maximum J(c) value of screen-printed YBCO film, fi red by the solid-phase sintering method, was about 470 A cm(-2) at 77 K, O T. This value was about four-fifths of those for films on single- crystal YSZ substrates. (C) 1998 Elsevier Science S.A.