Specific Heat, Entropy, and Expansion Coefficient of Liquid Helium-Three

Abstract

The specific heat of liquid ${\mathrm{He}}^{3}$ has been measured over the temperature range 0.015 to 0.3\ifmmode^\circ\else\textdegree\fi{}K at pressures of 0.12, 6.45, 14.6, 21.4, and 28.8 atm. The specific-heat curves have been fitted to polynomials suitable for the calculation of absolute entropies. The isobaric thermal expansion coefficient has been measured over the same temperature interval at pressures of 14.4, 21.1, and 28.5 atm and is found to be negative over the entire region investigated. The thermodynamic consistency of these two sets of measurements is discussed.