Growth mechanism of YBCO films in metal organic deposition method using trifluoroacetates

We report the theoretical analysis of YBCO growth during post annealing in the TFA-MOD process considering both the diffusion in the boundary layer and the growth kinetics at the precursor/YBCO interface. As a result, we could obtain the analytical solution of the growth rate of YBCO. Subsequently, the unknown parameters in this solution were evaluated by the experimental measurements of the growth rate. The experimental results of the growth rate showed that it was independent of the film thickness and proportional to the square root of the water vapor pressure. These results suggested that the mass transfer in the gas boundary layer limited the growth rate. This model reveals a basic idea of the mechanism to determine the steady state growth rate,, and could explain the experimental results. In addition, it predicts that the growth rate can be estimated from the water vapor pressure of the inlet gas. Consequently, it was confirmed that this growth model is effective for understanding of the growth kinetics in the TFA-MOD process.