GROWTH OF Y-BA-CU-O SUPERCONDUCTING THIN-FILMS BY ULTRASONIC SPRAY PYROLYSIS

Y-Ba-Cu-O films, 1-3-mu-m thick, on yttria-stabilized zirconia substrates have been prepared by ultrasonic spray pyrolysis of aqueous-glycerol solutions containing yttrium, barium and copper nitrates. The effect of glycerol in the metal nitrate solutions on the growth process of Y-Ba-Cu-O films has been investigated. The study shows that aqueous-glycerol nitrate solutions provide better films than aqueous-nitrate solutions. The YBa2Cu3O7-x film on yttria-stabilized zirconia substrate prepared from aqueous-glycerol nitrate solutions shows a sharp superconducting transition and a T(c) zero above 90 K; this film has a preferential orientation of the crystallite c axis of the orthorhombic structure perpendicular to the substrate surface. It can be said that spray pyrolysis of nitrate solutions provides a viable technique for the preparation of high quality, inexpensive Y-Ba-Cu-O superconducting films over large areas, on wires, ribbons or fibres.