Thermal decomposition of precursor of YBa2Cu3O7-δ superconducting layer

The aim of this paper is to investigate the thermal decomposition and synthetic reaction kinetics of superconducting material and provide the reference data for the production process of high-temperature superconducting tapes. First, a precursor solution was prepared as acetate of components of YBa 2 Cu 3 O 7-δ (YBCO) material and various thermal analyses were performed using the powders obtained by drying and grinding processes. Then, the synthesis mechanism of YBCO superconducting phase and the kinetic parameters were obtained using the universal differential, integral and multi-rate scanning Kissinger methods. From the results, it could be found that the thermal decomposition was divided into four stages characterized by weight loss from 25 to 900 °C. The thermal decomposition processes in the second and third stages follow the chemical reaction model with different reaction orders of 3/2 and 3, the average apparent activation energies of the second and third stages calculated by the integral and the differential methods were 153 and 156 kJ/mol, respectively. Specifically, the fourth stage for synthesis reaction of YBCO phase follows the random nucleation and subsequent growth ( n = 2) model, the activation energy and pre-exponential factor of this stage were 222 kJ/mol and 2.34 × 10 10 /min, respectively.