METAL-ORGANIC DEPOSITION OF YBCO AND BSCCO PLATELETS, FILMS AND WIRES

Metal-Organic Deposition (MOD) technique has been used for the first t ime, in the spray version, to obtain thin and thick films of BSCCO on substrates like MgO and Ag and, in the dipping version, to deposit YBC O thick films directly on a thin Ag wire. Diffraction data show that B SCCO films are textured and oriented with their normal axis along the [001] direction. Electron microprobe data confirm a strong presence of (2212) modification of BSCCO. The YBCO/Ag wire is very uniform, as co nfirmed by SEM micrographs, and shows a transition temperature around 90 K. Thick films and platelets of YBCO have been also prepared by met alorganic solution spraying and by using a commercial microwave oven i n the last annealing stage, reducing the duration of this step from se veral hours to about 65 minutes. YBCO samples show good stoichiometry, a very smooth surface morphology and transition temperatures, as meas ured by a.c. susceptometry at low magnetic fields, which are around 90 K. Films, deposited on MgO, are oriented with their growth ads along the [005] direction and, if deposited on SrTiO3, along the [006] direc tion. Physical, chemical, structural and morphological properties of t hese HTSC samples obtained by MOD are presented and discussed, with th e conclusion that this technique, which is simple, flexible, suitable for large surface areas, for ribbons and for wires, has achieved a goo d stage of maturity.