A study of thermal and dielectric behavior of melaminium perchlorate monohydrate single crystals

Single crystals of melaminium perchlorate monohydrate (MPM) have been grown from aqueous solution by slow solvent evaporation method at room temperature. X-ray powder diffraction analysis confirms the title crystal crystallizes in the triclinic (P-1) structure and the calculated lattice parameters are a = 5.6275 +/- A 0.0780 , b = 7.6926 +/- A 0.1025 , c = 12.0878 +/- A 0.2756 , alpha = 103.89 +/- A 1.01A degrees, beta A = 94.61 +/- A 0.92A degrees, gamma A = 110.22 +/- A 0.81A degrees, and V = 468.95 (3). The thermal decomposition behavior of MPM has been studied by means of thermogravimetric analysis at three different heating rates 5, 10, and 20 A degrees C min(-1). The values of effective activation energy (E (a)), pre-exponential factor (ln A) of each stage of thermal decomposition for all heating rates were calculated by model free method: Kissinger, Kim-Park, and Flynn-Wall method. A significant variation of effective activation energy (E (a)) with conversion (alpha) indicates that the process is kinetically complex. The linear relationship between the A and E (a) values was established (compensation effect). Dielectric study has also been carried out and it is found that both dielectric constant (epsilon') and dielectric loss (epsilon aEuro(3)) decreases with increase in frequency.