Thermogravimetric Analysis of Simultaneous Decomposition and Formation of MgB2

This study provides the simultaneous thermogravimetric (TGA) decomposition and formation of MgB2. This thermal decomposition of MgB2 to MgB4 was investigated to determine the kinetic barriers associated with the decomposition process. At the same time, the formation of MgB2 from MgB4 was also studied. A list of models available from the literature was also validated in the present study by using the Coats-Redfern equation to determine the mechanism involved in the decomposition and formation reactions. A second order reaction model was more linearly fitted with the CR equation than other available models. A computational approach was used to determine the precise reaction order (n = 2.2) for both decomposition and formation. The activation energy of decomposition was 205.81 +/- 1.5 kJ/mol and formation was 241.5 +/- 2.6 kJ/mol, both of which are in close agreement with the literature. The standard formation enthalpy of MgB2 (-18.16 +/- 1.78 kJ/mol) and MgB4 (-13.86 +/- 0.71 kJ/mol) was also obtained.