1982/08/01 by John W. Ward, P. D. Kleinschmidt, R.G. Haire · 2 citations
Chemistry · Earth and Planetary Sciences · Engineering · #Chemical Thermodynamics and Molecular Structure #High-pressure geophysics and materials #Thermodynamic and Structural Properties of Metals and Alloys
paper · doi:10.1063/1.443975
openalex publication_date 1982/08/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
The vapor pressure of 249Bk metal has been measured over the range 1100–1500 K, using combined target and mass spectrometric Knudsen effusion techniques. Vapor pressure data are combined with an appropriate estimate for the solid heat capacity and the estimated crystal entropy S°298, to produce enthalpy, entropy, and free energy functions from 298 to 2000 K. The vapor pressures are described by the equations: Log10 P(atm) = −(15 718 ±253)/T+578±0.21 [solid, 1107–1319 K], Log10 P(atm) = −(14 902 ±244)/T+5.14±0.17 [liquid, 1345–1528 K] from which we calculate Δ H°298 (2nd law) = 73 960±1150 cal/mol [solid], Δ H°298 (2nd law) = 73 980±1120 cal/mol [liquid], and Δ H°298 (3rd law) = 74 220±180 cal/mol [solid and liquid].