Kinetic Studies of the Non-Isothermal Decomposition of Unirradiated and Γ-Irradiated Gallium Acetylacetonate

Abstract

The non-isothermal decompositions of unirradiated and γ-irradiated (102 kGy) gallium acetylacetonate Ga(acac)3 were carried out in static air. The results showed that the decomposition of Ga(acac)3 proceeds through multiple decomposition steps in the temperature range 150-310°C to produce Ga2O3 as a final solid residue. Kinetic studies of the non-isothermal data for both unirradiated and γ-irradiated Ga(acac)3 were performed using both model-fitting and model-free approaches. In a model-fitting approach, the kinetic triplet, i.e. The apparent activation energy Ea, the pre-exponential factor ln A, and the reaction model f(α), were analyzed and calculated using the methods of Coats and Redfern, and Kennedy and Clark. In the model-free approach, the non-isothermal data for both unirradiated and γ-irradiated samples were analyzed using the Flynn-Wall-Ozawa (FWO), Tang (T), and Vyazovkin (Vyz) isoconversional methods. The results of application of model-free and model-fitting approaches to the non-isothermal data for both unirradiated and γ-irradiated Ga(acac)3 were compared and evaluated to deduce the most probable kinetic triplet that describes correctly the thermal behaviour of Ga(acac)3. No significant changes were observed in the behaviour of unirradiated and γ-irradiated Ga(acac)3 either as regards their thermal decomposition or the calculated kinetic parameters.