Development of Low-Fluorine Solution for YBCO Film Growth
We developed a simple and stable precursor solution containing low fluorine content to fabricate YBa2Cu3Oy (YBCO) films on CeO2/YSZ/CeO2 buffered NiW substrates. The fluorine content in the precursor solution could be controlled at 23.1% by tuning the ratio of barium trifluoroacetate to barium acetate. Fast pyrolysis process and smooth surface of YBCO precursor films could be acquired by using the low-fluorine solution. The phase, texture, microstructure, and superconducting properties of YBCO film were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, and four-probe method, respectively. The crystallized YBCO film showed good out-of-plane and in-plane textures. A high critical current density Jc of ~3 MA/cm 2 (77 K, 0 T) could be obtained in the YBCO/CeO2/YSZ/CeO2/NiW sample derived from the low-fluorine solution. The results indicate that the controllable fluorine content solution could be useful for epitaxial growth of YBCO films on buffered NiW substrates.