Fundamental studies of metal fluorination reactions. Progress report, May 1, 1976--April 31, 1977
The present research is being undertaken to study some fundamental thermodynamic and transport properties and detailed mechanisms pertinent to metal fluorination reactions. The program consists of determining the following properties using solid-state, CaF/sub 2/-electrolyte galvanic cells: (A) solubility and diffusivity of fluorine in metals, specifically nickel, and (B) the nature of the point defects (type, concentration and mobility) in metal fluorides as a function of fluorine partial pressure, temperature and impurity concentration. The latter study encompasses the study of the electrical conductivity of metal fluorides under thermodynamically well-defined conditions. Another objective of the program is to design and construct a fluorine probe for the measure of fluorine chemical potentials in gaseous environments. The probe must be evaluated in oxygen-containing atmospheres which might limit its accuracy and lifetime. For several technical reasons, the specific experimentation has deviated somewhat from that originally proposed. For two reasons, a probable phase change in CaF/sub 2/ at a temperature around 1175/sup 0/C and a thermal expansion coefficient which differs greatly from solid nickel, CaF/sub 2/ single crystal electrolytes could not yet be interfaced perfectly to solid nickel for electrochemical studies. However, these problems were avoided by the successful substitution of copper for nickel in the studies of solubility and diffusivity. Some problems also arose in the study of the electrical conductivity of NiF/sub 2/, namely, only relatively impure NiF/sub 2/ was available, and NiF/sub 2/ exhibited poor mechanical stability as electrodes. Therefore, the proposed methods were used mostly for the study of B-PbF/sub 2/, for which previous studies also provided values for comparison. With the experience gained from the work reported here, future experimentation with nickel metal and NiF/sub 2/ should be successful.
- Research Organization:
- The Ohio State Univ., Columbus, OH (United States)
- DOE Contract Number:
- EY-76-76-S-02-2671
- OSTI ID:
- 7328462
- Report Number(s):
- COO-2671-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diffusivity and solubility of fluorine in solid nickel from electrochemical measurements
Fundamental studies of metal fluorination reactions. Third annual progress report
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
METALS
FLUORINATION
NICKEL
CALCIUM FLUORIDES
COPPER
DIFFUSION
RESEARCH PROGRAMS
SOLUBILITY
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHEMICAL REACTIONS
ELEMENTS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HALOGENATION
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties