Kinetic analysis of thermal decomposition reactions. VII. Effect of radiation and doping on the thermal decomposition of BaCO3–TiO2and SrCO3–TiO2crystalline mixtures

DTA–TG techniques were applied to study the thermal decomposition and reactivity in intimately mixed powders of barium or strontium carbonate and titanium dioxide. The results showed that the temperature for the thermal decomposition of BaCO3–TiO2mixtures precedes the decomposition of pure BaCO3by about 250 °C, whereas the decomposition of SrCO3–TiO2mixtures precedes the decomposition of pure SrCO3by about 60 °C. Kinetic analysis of the isothermal data in view of various solid-state reaction models showed that the reaction is best described by the phase boundary models. The effects of 60Co γ irradiation and of doping the metal oxide with Li+or Cu2+ions on the thermal decomposition reactions were investigated. Keywords: titanates, thermal decomposition, doping, irradiation effects.