Fundamental studies of metal fluorination reactions. Annual progress report
Solid-state electrochemical methods are being used to determine structural, thermodynamic, and transport properties in materials pertinent to the fluorination of metals at elevated temperatures. The solubility and diffusivity of fluorine in solid metals (initially nickel) are being studied by a potentiostatic electrochemical procedure by which changes in an impressed cell voltage induces changes in the activity of fluorine at a metal/electrolyte interface while the recording of the resulting cell current as a function of time can be interpreted to yield the desired quantities. Defect structures in metal fluoride compounds (initially NiF/sub 2/ and PbF/sub 2/) are being studied through measurements and interpretation of the electrical conductivity. The variation in the conductivities of the pure and impurity-doped compound as a function of fluorine activity can be interpreted to establish the partial ionic and electronic conductivities of the compounds, and the concentrations and mobilities of the carriers. Finally, a CaF/sub 2/-electrolyte probe (gauge) is being developed for the measurement of fluorine activities in gases at elevated temperatures. The literature has been searched and studied. Experimental materials have been ordered and two high-temperature electrochemical systems have been constructed and tested. The electrical instrumentation has been tested and calibrated. A porous graphite electrode was found to be effective in fixing and transmitting fluorine activities which are set electrochemically at one graphite/electrolyte interface. This preliminary success establishes the intended means for the variation of fluorine activity in the electrical and conductivity measurements. Coexistence electrodes of nickel plus nickel fluoride at 850-950/sup 0/C have been found to remain essentially reversible despite current passage up to significant current densities. (auth)
- Research Organization:
- Ohio State Univ., Columbus (USA). Dept. of Metallurgical Engineering
- DOE Contract Number:
- E(11-1)-2671
- OSTI ID:
- 7366353
- Report Number(s):
- COO-2671-1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
METALS
FLUORINATION
NICKEL
CRYSTAL DEFECTS
DIFFUSION
ELECTRIC CONDUCTIVITY
FLUORINE
NICKEL FLUORIDES
RESEARCH PROGRAMS
THERMODYNAMICS
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENATION
HALOGENS
NICKEL COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties