Sodyum nitrit (NaNO2) ve amonyum sülfatın ((NH4)2SO4) Raman kipleri için sönüm katsayılarının faz geçişleri yakınlarında sıcaklığa bağımlılığı

In this study, we analyzed the temperature dependence of the order parameter, damping constant and the activation energy in a wide range of temperatures for the NaNO2 modes (B1 asymmetric, B2 libration, B1 libration and A2 libration) and (NH4)2SO4 modes ( , 364 cm-1 libration, 394 cm-1 libration). We used the order parameter equation predicted from the molecular field theory to calculate the order parameters in NaNO2 and (NH4)2SO4. By using these calculated values of the order parameter, we computed the damping constants for the modes of NaNO2 and (NH4)2SO4studied here. We related the theoretical values of damping constants to the experimental results. By using the calculated damping constants in the Arrhenius plots , we determined the activation energy values of all modes of both NaNO2 and (NH4)2SO4 in different temperature ranges.