Raman studies of phase transitions in ferroelectric [C2H5NH3]2ZnCl4

The present paper accounted for the synthesis, differential scanning calorimetric and vibrational spectroscopy of C₂H₅NH₃]₂ZnCl₄grown at room temperature. Differential scanning calorimetric (DSC) disclosed five phase transitions at T₁=231 K, T₂=234 K, T₃=237 K, T₄=247 K and T₅=312 K. The temperature dependence of the dielectric constant at different temperatures proved that this compound is ferroelectric below 238 K. Raman spectra as function temperature have been used to characterize these transitions and their nature, which indicates a change of the some peak near the transitions phase. The analysis of the wavenumber and the line width based on the order–disorder model allowed to obtain information relative to the thermal coefficient and the activation energy near the transitions phase.