THE MECHANISM OF COPPER-OXIDE SEGREGATIONS IN Y-BA-CU-O/YSZ THIN-FILMS

Experimental results show that copper-oxide segregation occurs by chemical reaction at the interface between Y-Ba-Cu-O thin films and ZrO2 substrates, which results in a layer of BaZrO3 (thickness ∼0.8 μm). A "buffer layer" of silver inbetween the film and substrate as a barrier for the diffusion of Ba atoms into YSZ or the formation of silver-copper alloys during a high temperature annealing process prevents the copper oxide segregation. It is concluded that BaZrO3 is a prospective candidate substrate for the fabrication of high-Tcthin films. © 1990 Springer-Verlag.