The thermodynamic properties of liquid 3He- 4He mixtures between 0 and 20 atm in the limit of absolute zero temperature

Abstract

The presently existing thermodynamic data of liquid 3He- 4He mixtures between 0 and 20 atm in the limit of absolute zero temperature are presented in a coherent way, without reference to models, through constructing the thermodynamic surface ε( n 3, n 4), where ε is the energy density and n 3, n 4 are the molar densities. The chemical potentials are the partial derivative of ε. The construction is made through the information contained in the existing thermodynamical data. The geometrical meaning of the surface whose coordinates are the energy density and the molar densities of both components is explained. In the pressure range considered the energy density and the chemical potentials are determined as a function of the molar densities. Details of the thermodynamic functions are summarized in the tables at the end of the article. Special attention is given to the saturated solution curve and the one-phase region in which the energy density appears to be expandable not in integral but in fractional powers of the 3He density.