Numerical study on crystal growth process in YBCO film fabricated by TFA-MOD method

To fabricate high-J(c) coated conductor of YBa2Cu3O7-X (123) film, metal-organic deposition (MOD) process using precursor solution of trifluoroacetates (TFAs) is one of the most promising low cost non-vacuum methods. However, details of the growth process and the mechanism of 123-crystal growth are still unknown. To clarify the growth mechanism of 123-film, the growth processes of 123-crystals were studied by the experimental method and the numerical method. Microstructures of growing 123-crystals were revealed through transmission electron microscopy (TEM) observations of the specimens quenched during the growth of 123-crystals on LiAlO3 (LAO) substrates. The growth process of faceted 123-crystals with various crystal orientations was simulated by the two-dimensional numerical method using c-axis and a-axis growth rate functions. The growth processes and the microstructures of 123-crystals were visualized by the simulation. The meandering of crystal boundaries, overgrowth of preferred oriented crystals. and the effects of initial distributions of nucleated crystals and particles were studied. (c) 2008 Elsevier B.V. All rights reserved.