EFFECT OF BA-CA-CU PRECURSOR MATRIX ON THE FORMATION AND PROPERTIES OF SUPERCONDUCTING TL2BA2CAN-1CUNOX FILMS - A COMBINED METALORGANIC CHEMICAL-VAPOR-DEPOSITION AND THALLIUM VAPOR DIFFUSION APPROACH

Superconducting thin films of the Tl2Ba2CaCu2Ox (2212) and Tl2Ba2Ca2Cu 3Ox (2223) phases have been prepared through a vapour diffusion. The e ffects due to the nature of the BaCaCuO(F) precursor matrix on the for mation of the TlBaCaCuO phase film have been investigated. Fluorinated [BaCaCuO(F)] matrices have been deposited from Ba(hfa)(2) . tetraglym e, Ca(hfa)(2) . tetraglyme and Cu(acac)(2) via metalorganic chemical v apour dc position (MOCVD) on yttria-stabilized zirconia (YSZ) substrat es. Both fluorinated [BaCaCuO(F)] and unfluorinated (BaCaCuO) matrices proved suitable for vapour diffusion thallium incorporation using sel ected Tl2O3:BaO:CaO:CuO mixtures. The formation of the superconducting 2212 and 2223 films is discussed depending upon the fluorinated and u nfluorinated nature of the precursor matrices.