Texture formation and superconducting properties of YBa{sub}2Cu{sub}3O{sub}x thin films prepared by solution process on LaAlO{sub}3 single crystals

摘要

YBa{sub}2Cu{sub}3O{sub}x (YBCO) thin films were fabricated by the trifluoroacetate (TFA) process on LaAlO{sub}3 (LAO) single crystal in an argon atmosphere. We focused on lowering the heat treatment temperature by decreasing the oxygen partial pressure to adopt the TFA process to metallic substrates. YBCO phase formation was checked by measuring T{sub}c with the inductive method. In-plane and out-of-plane film textures were evaluated by phi-scan and omega scan, respectively. Raman spectroscopy was used to estimate grain connectivity, in-plane texture, and second-phase formation of the films. Although Raman spectroscopy revealed some evidence of cation disorder, the film prepared at 750°C shows a sharp superconducting transition at 91 K and critical current density of 1.3 MA/cm{sup}2 at 77 K. Optimal heat treatment temperature was 750°C in the argon atmosphere, which is consistent with the thermodynamic estimate that heat treatment temperature decreases as oxygen partial pressure decreases.