Non-isothermal solid-state synthesis kinetics of the tetragonal barium titanate

The solid-state synthesis kinetics of the barium titanate is investigated through thermogravimetry analysis (TGA), and derivative thermogravimetry (DTG). The XRD results confirmed the formation of pure tetragonal BaTiO3 after thermal analysis. The thermodynamic parameters (Delta H, Delta S, Delta G) are calculated for all possible reactions involved during the formation of BaTiO3. The thermodynamic analysis predicted the formation of intermediate compounds (BaO, Ba2TiO4). The thermal kinetic analysis is also performed by using the deconvolution kinetic method. The thermal profile is convoluted in three peaks and the kinetic triplets are calculated. The activation energy is calculated by using the iso-conversional KAS kinetic model based on the Straink approximation. The order of the average activation energy is Peak III (225.81 kJ/mol) > Peak II (223.88 kJ/mol) > Peak I (197.67 kJ/mol). The reaction mechanism and pre-exponential are identified by the integral master plot method. The F1, R2 and A4 reaction mechanisms dominated the reaction occurring in peak I, peak II and peak III, respectively.