A Novel Rapid Pyrolysis of Non-fluorine MOD-Derived YBCO Thin Films

A novel rapid pyrolysis method at 5 Pa with argon as background gas was proposed to prepare YBa 2 Cu 3 O 7-δ (YBCO) films by non-fluorine metal organic solution deposition (MOD). The YBCO sol–gel films were pyrolyzed about 29 min, warm up from 20 to 600 ℃, which is less than the one-twentieth of conventional pyrolysis time for non-fluorine MOD processing. The influence of the low-vacuum and the rapid decomposition on the microstructures of YBCO precursor films were investigated, while the high-temperature firing process was further optimized for epitaxially grown YBCO films. The results show that most of the defects generated in the low-vacuum processing can be eliminated nearly by increasing firing time up to 60 min, and finally the textured YBCO films with denser and smoother morphologies were obtained. The results of both Raman and X-ray spectra show that the c -axis growth is superior to the a -axis growth, leading to a better critical current density J c of 1.3 MA/cm 2 (77 K, self-field).