Analysis of the Specific Heat and Calculation of the Entropy, Enthalpy, and Free Energy Close to the Lower Phase Transition in Imidazolium Perchlorate

Abstract

The abnormal behavior of the specific heat of Imidazolium Perchlorate (Im-ClO4) was analyzed in terms of the power-law formula (including critical exponent α and fitting parameter JA) derived from the Ising model around the lower phase transition temperature of TC = 247 K. Moreover, the temperature dependence of some thermodynamic functions such as entropy, enthalpy, and the Gibbs free energy were calculated using the values of α and 𝐽𝐴 extracted from the observed specific heat data of Im-ClO4.