KINETIC STUDIES OF THE NON-ISOTHERMAL DECOMPOSITION OF UNIRRADIATED AND γ-IRRADIATED GALLIUM ACETYLACETONATE

The non-isothermal decompositions of unirradiated and gamma-irradiated (10 2 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 degrees C to produce Ga2O3 as a final solid residue. Kinetic studies of the non-isothermal data for both unirradiated and gamma-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 E-a, the pre-exponential factor In A, and the reaction model f(alpha), 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 gamma-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 gamma-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 g-irradiated Ga(acac) 3 either as regards their thermal decomposition or the calculated kinetic parameters.