Reactive liquid phase sintering of solution-derived YBa₂Cu₃O_7−x superconducting thin films: Part I. Ambient and precursor effects on BaO–CuO liquid phase formation

Processing atmosphere and precursor effects on liquid phase formation were investigated in the BaO–CuO thin film system. Liquid phase was observed at a significantly lower temperature (∼620 °C) under N₂ atmosphere with carboxylate solution precursors. In the processing of the YBCO oxide superconductors, formation of the liquid phase facilitated the decomposition of BaCO₃ and crystallization of the YBCO grains. Larger grains and greater (00l) preferred orientation were also observed in the YBCO films prepared with the presence of the liquid phase.