Textured YBCO Films Derived from Low-Fluorine-Content Solution

Abstract

with yttrium, barium, copper acetates as starting materials, a low-fluorine-content solution was prepared. YBa2Cu3O7-x (YBCO) films on LaAlO3 (LAO) single crystal substrates were fabricated by a new TFA-MOD method. Solution-derived YBCO films exhibited epitaxial growth, which was confirmed by X-ray diffraction (XRD). The humidity of the furnace atmosphere during annealing process influences the texture of YBCO film. Under high-humidity of furnace atmosphere, a-oriented grains, which were confirmed by scanning electron microscopy (SEM), were generated on film surface. High-resolution transmission electron microscopy (HRTEM), however, indicated that although a-axis oriented grains formed on the film surface, c-axis oriented grains occupied the area near the YBCO/LAO interface. High-performance YBCO films with Tc above 90K, and Jc more than 106A/cm2 at 77 K and zero magnetic field were obtained.