PREPARATION OF YBCO SUPERCONDUCTOR THIN-FILM BY SPIN-COATING METHOD WITH METAL-ORGANIC PRECURSORS

YBCO thin film was prepared by the spin-coating method with metal-orga nic precursors. The precursors were synthesized by reacting metal acet ates with 2-ethylhexanic acid or by reacting metal halides with ammoni um 2-ethylhexanate directly. After proper heat treatments, YBCO film w ith T(c, onset) = 80 K and T(c, zero) = 77 K was obtained. SEM studies of a sample prepared at 990-degrees-C showed the presence of CuO and Ba2YCuO5 (211 phase). This suggested the transient presence of a liqui d phase which had been observed in preparing YBCO bulk material by the melt-texture method before the formation of YBCO phase. Furthermore, many voids were observed in the as-obtained film. These might be the o rigin of the relatively low T(c,zero) temperature.