skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Vapor pressure and thermodynamics of actinide metals

Abstract

Precise vapor pressure measurements by target collection/mass spectrometric Knudsen effusion techniques were combined with crystal entropy estimates to produce self-consistent free-enrgy functions, permitting calculation of heats, entropies and free energies from 298/sup 0/K to the highest temperatures of measurement. The vapor pressures and thermodyamics of vaporization of americium, curium, berkelium, and californium are compared in terms of electronic structure and bonding trends in the trans-plutonium elements. These resuslts are contrasted with the behavior of the early actinides, with attention to energy states and possible effects of f-electron bonding. 9 figures, 4 tables.

Authors:
 [1]; ; ;
  1. (Los Alamos Scientific Lab., NM)
Publication Date:
OSTI Identifier:
6205013
DOE Contract Number:
W-7405-ENG-48
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Symp. Ser.; (United States); Journal Volume: 131
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; AMERICIUM; THERMODYNAMIC PROPERTIES; VAPOR PRESSURE; BERKELIUM; CALIFORNIUM; CURIUM; ACTINIDES; ENTROPY; FREE ENERGY; KNUDSEN FLOW; MASS SPECTROSCOPY; MEDIUM TEMPERATURE; ELEMENTS; ENERGY; FLUID FLOW; GAS FLOW; METALS; PHYSICAL PROPERTIES; SPECTROSCOPY; TRANSPLUTONIUM ELEMENTS; TRANSURANIUM ELEMENTS; 400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials

Citation Formats

Ward, J.W., Kleinschmidt, P.D., Haire, R.G., and Brown, D.. Vapor pressure and thermodynamics of actinide metals. United States: N. p., 1980. Web. doi:10.1021/bk-1980-0131.ch010.
Ward, J.W., Kleinschmidt, P.D., Haire, R.G., & Brown, D.. Vapor pressure and thermodynamics of actinide metals. United States. doi:10.1021/bk-1980-0131.ch010.
Ward, J.W., Kleinschmidt, P.D., Haire, R.G., and Brown, D.. 1980. "Vapor pressure and thermodynamics of actinide metals". United States. doi:10.1021/bk-1980-0131.ch010.
@article{osti_6205013,
title = {Vapor pressure and thermodynamics of actinide metals},
author = {Ward, J.W. and Kleinschmidt, P.D. and Haire, R.G. and Brown, D.},
abstractNote = {Precise vapor pressure measurements by target collection/mass spectrometric Knudsen effusion techniques were combined with crystal entropy estimates to produce self-consistent free-enrgy functions, permitting calculation of heats, entropies and free energies from 298/sup 0/K to the highest temperatures of measurement. The vapor pressures and thermodyamics of vaporization of americium, curium, berkelium, and californium are compared in terms of electronic structure and bonding trends in the trans-plutonium elements. These resuslts are contrasted with the behavior of the early actinides, with attention to energy states and possible effects of f-electron bonding. 9 figures, 4 tables.},
doi = {10.1021/bk-1980-0131.ch010},
journal = {ACS Symp. Ser.; (United States)},
number = ,
volume = 131,
place = {United States},
year = 1980,
month = 1
}
  • Precise vapor pressure measurements by target collection/mass spectrometric Knudsen effusion techniques were combined with crystal entropy estimates to produce self-consistent free-energy functions, permitting calculation of heats, entropies and free energies from 298 K to the highest temperatures of measurement. The vapor pressures and thermodynamics of vaporization of americium, curium, berkelium, and californium are compared in terms of electronic structure and bonding trends in the transplutonium elements. These results are contrasted with the behavior of the early actinides, with attention to energy states and possible effects of f-electron bonding. 9 figures, 4 tables.
  • The magnesinm vapor pressures over copper- magnesium and nickel - magnesium alloys were measured by the Knudsen effusion method in the temperature range, 400 to 1100 deg K. The free energies, enthalpies and entropies of formation of Mg/sub 2/Cu, MgCu/sub 2/, Mg/sub 2/Ni/sub 2/ and MgNi/sub 2/ were c omputed from the vapor pressure data. The results indicate that the bond strengths in the nickel - magnesium compounds are appreciably greater than in the corresponding copper-magnesium compounds. (auth)
  • Vapor pressures of the tantalum-hydrogen system were measured for temperatures ranging from 164 to 402 deg C and for alloys containing from 0.1 to 33 1/3 at. % hydrogen. The data for temperatures between 300 and 400 deg were treated to obtain partial molal free energies, entropies and enthalpies, and the free energies, entropies and heats of formation of the solid solutions. The data are in agreement with Sievert's Law only at intermediate concentrations. Positive deviations occur at high concentrations due to a progressive filling of interstitial sites and a reduction in the entropy of the system. Complex behavior ismore » observed in dilute solutions, originating, it's thought, with gaseous impurities (oxygen and nitrogen) in the sample. The partial heat of vaporization is about half as large in dilute solutions as in concentrated solutions and the entropy of dissolved hydrogen is unexpectedly high. The reason for this behavior is not clear. (auth)« less