Solid State Reaction Mechanisms of the LiMnPO4 Formation Using Special Function and Thermodynamic Studies

LiMnPO4 was successfully synthesized via thermal decomposition processes of the synthesized MnHPO4 center dot 3H(2)O precursor. Thermogravimetry/differential thermal gravimetry/differential thermal analysis, Fourier transform infrared, atomic absorption spectrophotometry, X-ray diffraction, and scanning electron microscopy techniques were employed for the characterization of the samples. Three thermal decomposition steps in the sequence of dehydration, polycondensation, and decarbonization were observed. The iterative Kissinger-Akahira-Sunose method was used to calculate the exact E-alpha values. Regions I and II of the first, second, and final steps were confirmed to be single-step kinetic processes with the unique kinetic triplets. The most probable mechanism functions were found to be R-3, R-2, A(2), and P-4 corresponding to contracting sphere, contracting cylinder, assumed random nucleation (its subsequent growth), and nucleation processes, respectively. The pre-exponential factors, A, were calculated using E-alpha and g(alpha). The thermodynamic functions of the transition-state complexes were evaluated from the pre-exponential factors. The kinetic triplets, reaction mechanisms, and calculated thermodynamic functions of the formation of LiMnPO4 are reported for the first time.