Kinetic analysis on the synthesis of Mg0.95Zn0.05TiO3 microwave dielectric ceramic by polymeric precursor method

Abstract

Thermo gravimetric-differential scanning calorimetry (TG-DSC) was used to analyze the thermal decomposition of polymeric precursor of Mg0.95Zn0.5TiO3 at different heating rates in the flow of air atmosphere. The kinetic parameters of the reaction were calculated using isoconversional methods. Three dimensional diffusion reaction (Jander); g(α)=[1−(1−α)1/3]2 was proposed mechanism function for the reaction. By using Flynn–Wall–Ozawa model the calculated values of the average activation energy, pre-exponential factor and order of the reaction were found to be 129.33kJ/mol, 1.04×108min−1, and 2.00, respectively. Whereas in the Kissinger–Akahira–Sunose model corresponding values were 123.88kJ/mol, 2.95×107min−1, and 2.09, respectively. The thermodynamic parameters such as enthalpy, Gibbs free energy and entropy of activation calculated at the peak temperature were noted to be 120.46kJ/mol, 228.69kJ/mol, and −146.63J/molK, respectively. Moreover, phase, microstructure and microwave dielectric properties of Mg0.95Zn0.5TiO3 are discussed.