Thermodynamics of the sublimation and disproportionation of uranium trifluoride

Journal Article · Sat May 01 04:00:00 EDT 1982 · Dokl. Phys. Chem. (Engl. Transl.); (United States)

OSTI ID:6601053

Gorokhov, L N; Smirnov, V K; Khodeer, Yu S

A mass-spectrometric investigation of the thermodynamics of sublimation and of the disproportionation of uranium trifluoride was carried out. The work was performed in an MS1301 magnetic mass-spectrometer designed for studying the vaporiation processes of difficulty volatile substances. The substance to be tested was evaporated from a molybdenum effusion cell with a graphite lining. Uranium trifluoride was obtained from the tetrafluoride by reduction with aluminum, after first distilling the tetrafluoride in high vacuum. The reduction reaction was carried out in an effusion cell placed in the evaporation unit of the mass spectrometer, and this enabled the course of the reaction to be followed. The ionization potentials of the UF/sub 4/ and UF/sub 2/ molecules were found in a separate experiment, was used to calibrate the electron energy scale. Silver evaporated from the effusion cell simultaneously with UF/sub 4/ was used as the standard in measuring the ionization potential of UF/sub 4/. In all cases except that of UF/sub 2/ the extrapolated difference method was used in the treatment of the ionization efficiency curves; in the case of UF/sub 2/, because of the low intensity of the UF/sub 2/ ion current, the ionization potential was determined by the linear extrapolation method. In two experiments, 25 measurements of UF/sup +//sub 3/ and 23 measurements of UF/sup +//sub 4/ were made over the range 1252-1468/sup 0/K. At the end of the evaporated process in these experiments, a rapid and simultaneous fall of the UF/sup +//sub 3/ and UF/sup +//sub 4/ intensities occurred, which characterised the pressure of a pure UF/sub 3/(c) phase.

• Research Organization: Academy of Sciences of the USSR, Moscow
• OSTI ID: 6601053
• Journal Information: Dokl. Phys. Chem. (Engl. Transl.); (United States), Journal Name: Dokl. Phys. Chem. (Engl. Transl.); (United States) Vol. 261:1-3; ISSN DKPCA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ACTINIDE COMPOUNDS
CHEMICAL REACTIONS
ENTHALPY
EQUATIONS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
OXIDATION
PHYSICAL PROPERTIES
REDUCTION
SUBLIMATION HEAT
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
TRANSITION HEAT
URANIUM COMPOUNDS
URANIUM FLUORIDES
VAPOR PRESSURE
VERY HIGH TEMPERATURE