Preparation of YBa2Cu3O7-delta powders by the thermal decomposition of a heteronuclear complex, CuY1/3Ba2/3(dhbaen)(NO3)(1/3)(H2O)(3)

YBa2Cu3O7-delta powders were prepared by the thermal decomposition of a het eronuclear complex, CuY1/3Ba2/3(dhbaen)(NO3)(1/3)(H2O)(3). The products of the complex thermal decomposition were analyzed by TG-DTA, XRD, SEM-Auger a nd XPS. The decomposition of the CuY1/3Ba2/3-complex was obtained at about 500 degrees C and the product was a mixture of oxides and carbonates. The f ormation of YBa2Cu3O7-delta proceeded at 800 degrees C, with a gradual deco mposition of the carbonates. A homogeneous distribution of each element, Y, Ba and Cu, was observed for the decomposed CuY1/3Ba2/3-complex by SEM-Auge r analysis. The binding energy values of Ba-3d5/2 and O1s photolines from B a and O in the superconductive lattice did not shift during the sputtering period. Furthermore, the formation of Ba rich regions on the surface was de pressed by using the complex as a starting material for homogeneous 123-oxi de, YBa2Cu3O7-delta. (C) 1999 Elsevier Science S.A. All rights reserved.