Specific heat at the superionic phase transition of cs3h(seo4)2

Abstract Electric conductivity and specific heat measurements were performed in the superionic phase transition region for Cs3H(SeO4)2. Activation energy of the conductivity was found to follow the ordering enthalpy of protons. The experimental value of entropy change at Ts, ▭ SII → I = 9.4 J/mol K, is in a good agreement with the value of configurational entropy change ▭ S = 9.13 J/mol K resulting from proton disordering.