Phase transition during sintering process before nucleation of TFA-MOD YBa2Cu3O7-? films

In order to bring new insights to the transformation mechanism of intermediate phase and its dependence on processing conditions via trifluoroacetate metal organic deposition (TFA-MOD) method, a series of quenching experiments with different annealing temperature and atmospheres were designed. It was revealed that the transformation temperature of Ba-Y-F solid solution was lower with increasing the partial pressure of water. Calculation results of the Gibbs free energy change with different partial pressure of HF and H₂O illustrated that the intermediate process is dominated by the exit diffusion of fluorine and the higher concentration of HF will inhibit the hydrolysis of barium fluoride.