Open AccessPressure-Volume-Temperature Relationships for Normal Deuterium Between 18.7 and 21.0 K
Author(s) -
L.A. Schwalbe,
E. R. Grilly
Publication year - 1984
Publication title -
journal of research of the national bureau of standards
Language(s) - English
Resource type - Journals
eISSN - 2376-5259
pISSN - 0160-1741
DOI - 10.6028/jres.089.013
Subject(s) - triple point , thermodynamics , compressibility , melting point , thermal expansion , volume (thermodynamics) , isobaric process , molar volume , melting curve analysis , isothermal process , deuterium , vapor pressure , bar (unit) , materials science , chemistry , physics , polymerase chain reaction , biochemistry , quantum mechanics , meteorology , gene , composite material
Analytical expressions are derived for the melting line and liquid equation of state of normal deuterium near the triple point. Melting pressures were measured between the triple point and 20.4 K. These results combined with existing pressure measurements along the saturated liquid-vapor curve fix an accurate value, T tp = 18.723 K, for the triple-point temperature. Data for the isothermal compressibility and thermal expansion coefficients of the liquid were taken over the temperature and pressure ranges 18.8 to 21.0 K and 4 to 70 bar, respectively. The liquid molar volume was measured at nine points below 20.4 K. All liquid PVT data are shown to be internally consistent. Measurements of the volume changes on melting are also presented. The heat of fusion and the solid molar volume at melting are deduced from these data. Also included are detailed comparisons of our results with existing data. A critical appraisal is given of all measured thermodynamic quantities in this regime.