Critical behaviour of the specific heat and the thermal expansion close to the melting point in ammonia solid III

Abstract

A linear correlation between the specific heat C_P and the thermal expansion α_p is established here for constant temperatures close to the melting pressure in ammonia solid III. For this correlation, the experimental data for the isothermal compressibility κ_T is analysed according to a power-law formula with the critical exponent γ and, the C_P and α_p are calculated as a function of pressure near the melting point in ammonia solid III. Values of the entropy changes with the temperature, which are extracted from linear plots of C_P against α_p, decrease as the temperature increases for the ammonia solid III prior to melting.