REACTIVE LIQUID-PHASE SINTERING OF YBA2CU3O7-X SUPERCONDUCTING THIN-FILMS .2. SINTERING MECHANISM AND FILM PROPERTIES

Reactive liquid phase sintering of the YBCO films prepared from carboxylate solution precursors was investigated. A liquid phase was formed by the BaO-CuO binary compound at 620-degrees-C, which facilitated the crystallization and growth of the YBCO grains. Strong capillary forces associated with the liquid phase sintering resulted in a dense, highly oriented microstructure. The YBCO films processed by this reactive liquid phase process showed T(c(zero)) = 90.2 K and J(c) = 1.3 X 10(5) A/cm2 at 77 K. The (006) rocking curve measurement indicated excellent grain orientation with a FWHM better than 0.2-degrees. A secondary ion mass spectroscopy (SIMS) study showed uniform film composition, and the film/substrate interaction zone was limited to almost-equal-to 0.1 mum. Average film roughness was about 32 nm.