Theoretical and experimental study on solid chemical reaction between BaCO3 and TiO2 in microwave field

Solid-state chemical reaction mechanism for the reaction between BaCO3 and TiO2 in microwave field was investigated based on X-ray power diffraction (XRD) data and theory of diffusion. The compositions of the resultant after reaction under different conditions were studied by employing XRD. The quantitative analyses based on XRD data showed the reaction in microwave field was quite different from that in the conventional method. A model was proposed to explain the change of the ratio between the reactant BaCO3, TiO2 and the resultant BaTiO3 for the chemical reaction. The formation kinetic of BaTiO3 from the BaCO3 and TiO2 was calculated by employing this theoretical model. The reaction rate between BaCO3 and TiO2 in microwave field was much higher than that in conventional method. The activation energy of the atomic diffusions in this solid chemical reaction is only 58 kJ/mol, which was only about 1/4 of 232 kJ/mol in the conventional value. The result suggests that the microwave field enhance atomic diffusion during the reaction.