386. The vapour pressure of plutonium tetrafluoride

Abstract

By C. J . MANDLEBERG and D. DAVIES.'lhe vapour pressure of plutonium tetrafluoride has been measured by Knudsen's effusion method, as modified by Phipps et al. Between 700" ant1 12OO0c, the vapour pressure can be represented by log,, p (mm. Hg) = 5-58 -10,04O/T; above 1200" a more volatile species occurs, whose vapour pressure can be represented by log,, p (mm. Hg) = 36.1 -54,18O/T.Above 1200" the residue remaining in the effusion pot is plutonium trifluoride and it is tentatively suggested that the species effusing above 1200" is the pentafluoride.

The Chemical Thermodynamic Properties of Plutonium Compounds

“…The vapor pressure of plutonium tetrafluoride has been determined by two teams of investigators, both using the Knudsen effusion technique (18,65). Mandleberg and Davies (65) found that between 700 and 1200°t he vapor pressure varies with the temperature according to the equation log P (mm) = 5.58 -10,040/T Above 1200°, where a more volatile species occurs, the vapor pressure is represented by log P (mm) = 36.1 -54,180/T Above 1200°the residue is plutonium trifluoride, and they tentatively suggest that the species effusing above 1200°is the pentafluoride.…”