Density fluctuations and the specific heat near the critical point. II

Abstract

In the earlier paper with this title it was concluded that the anomaly in the constant-volume heat capacity near the critical point arises from the density fluctuations, which originate from the increase in the compressibility. The specific heat depends upon the correlation length ξ, and factors influencing the effective value of ξ are considered in greater detail in the present paper. The density fluctuations have a feedback effect on the compressibility and the energy fluctuations arising from the specific-heat anomaly produce a feedback on the specific heat itself. It is shown that these feedback effects are relatively small. In considering the feedback on the compressibility we used the relationship which expresses the self-limitation of the fluctuations on account of the change of compressibility with density along the critical isotherm (previously we had considered other isotherms at the critical density). This allows a new derivation of one of the known exponent scaling relations.