Chemical method to prepare YBa2Cu3O7-x (YBCO) films by dipping onto SrTi(Nb)O-3 ceramics

Superconductor films of YBa2CU3O7-x (YBCO or 123) were formed by dip-coatin g onto SrTiO3 and Nb-doped SrTiO3 ceramic substrates. The precursor solutio n was based on Y-acetate, Ba-alcoholate in 2-methoxyethanol and Cu-butyrate , in an alcoholic solvent. Different heat treatments, up to a maximum tempe rature of 870 degrees C, were performed under oxygen and nitrogen atmospher e. The films onto Nb-doped SrTiO3 ceramic exhibit less reaction with the su bstrate as well as better superconducting properties. The best superconduct ing properties (T-c.onset = 91 K) were obtained in YBCO films, which were i nitially treated under N-2 flow UP to 625 degrees C, then under O-2 up to 8 70 degrees C, and subsequently reheated thoroughly under oxygen atmosphere with an annealing at 450 degrees C. (C) 2000 Elsevier Science S.A. All righ ts reserved.