THE REACTIONS OF MIXED CRYSTALS OF RARE EARTH FLUORIDES WITH FLUORINE GAS (thesis)

Technical Report · Thu Aug 01 00:00:00 EDT 1957

OSTI ID:4324435

Bryan, W P

The reactions of mixed crystals of rare earth fluorides with fluorine gas have been studied gravimetrically by determining the weight increases of mixed trifluoride samples upon exposure to fluorine at a pressure of 1 atmosphere and a temperature of 260 deg C. A special nickel helix balance was developed for directly studying these weight changes in an atmosphere of fluorine. The nature of the phases produced upon fluorination was studied by xray-diffraction methods. The following cerium-containing mixed trifluoride systems were studied over the whole range of compositions: Ce F/sub 3/ - LaF/sub 3/, CeF/sub 3/ -- YF/sub 3/, and y oxidized to the +4 state, and in a restricted range of the to the +4 state. The following terbium-containing mixed trifluoride systems were studied over the whole range of compositions: TbF/sub 3/--LaF/sub 3/ and TbF/sub 3/--YF/sub 3/. In neither case does complete oxidation of terbium to the +4 state occur after certain amounts of LaF/sub 3/ or YF/sub 3/ have been added to the TbF/sub 3/. The above results are explained thermodynamically and the DELTA F deg value for the reaction TbF/sub 3/ + 1/2 F/sub 2/= TbF/sub 4/ is estimated as being in the range between --278 calories and 0 calories at 250 deg C. (auth)

• Research Organization: California. Univ., Berkeley. Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-12-008332
• OSTI ID: 4324435
• Report Number(s): UCRL-3894
• Country of Publication: United States
• Language: English

Related Subjects

CERIUM FLUORIDES
CHEMICAL REACTIONS
CHEMISTRY
CRYSTALS
DIFFRACTION
FLUORIDES
FLUORINATION
FLUORINE
FREE ENERGY
GASES
GRAVIMETRY
INSTRUMENTS
LANTHANUM FLUORIDES
MIXING
NICKEL
OXIDATION
PRASEODYMIUM FLUORIDES
PRESSURE
QUANTITATIVE ANALYSIS
RARE EARTHS
TEMPERATURE
TERBIUM FLUORIDES
TESTING
THERMODYNAMICS
VARIATIONS
WEIGHT
X RADIATION
YTTRIUM FLUORIDES