MECHANISM OF MICROWAVE SYNTHESIZED BATIO3

The difference of intermediate products, microstructure and element co ncentration in the particles between microwave synthesized samples and conventional samples was responsible for the existence of non-thermal effect in the microwave field. The diffusions of Ba2+, Ti4+ in the mi crowave field were enhanced, so that the diffusion of Ti4+ could not b e neglected as in the conventional solid state reactions. The influenc es of the microwave field were mainly expressed as diffusion coefficie nt and the driving force of ionic motion. The intermediate phase Ba2Ti O4 which occurred in the conventional solid reaction was not found dur ing microwave syntheses. The quantity analyses based on XRD experiment al data show that the reaction dynamics in microwave is suitable for t he Carter equation. The activity energy for reaction of BaCO3 and TiO2 in the microwave field was 42.26 kJ/mol, which was only one fifth of the conventional reaction.