Superconducting oxide YBa2Cu3O7-δ was prepared by a sol-gel method, using nitrates or organometallic compounds as the starting reagents and ethylene glycol as the solvent. The processing parameters for gelation and pyrolysis were investigated. Single phase YBa2Cu3O7-δ was obtained when the as-prepared gel was heated above 900°C in air. Films were prepared by painting the gels on various substrates. The best superconducting films were obtained when the as-prepared gels were heated up to 950°C and annealed at 800°C on single crystals of SrTiO3 and at 550°C on Yttrium stabilized ZrO2 (YSZ) in O2, respectively. Films with Tc(zero) = 85K were obtained on the (100) surface of single crystal SrTiO3; oriented films with Tc(zero) = 82K on the (100) surface of YSZ formed. The films obtained from organic precursors showed Tc(onset) ∼90K, however, Tc(zero) was lower (∼50K) than those of the films formed from nitrates.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Materials Chemistry