DISSOLUTION KINETICS AT DISLOCATION ETCH PITS IN SINGLE CRYSTALS OF LITHIUM FLUORIDE. Technical Report No. 4
The dissolution kinetics, at dislocation sites, of lithium fluoride in water was studied as a function of time, temperature, unsaturation, and inhibitor concentration. The ledge theories are reviewed, and the experimental results on etch pit formation in lithium fluoride crystals are compared with the predictions of the theories. The etch pits were produced at dislocation-surface intersections on the {100} faces of lithium fluoride with an etchant consisting of a dilute solution of ferric fluoride in distilled water. Good agreement was obtained between experimental results and theoretical predictions with the exception of the dependence of pit slope on undersaturation. The concept of a timedependence in the kinetics of dissolving crystal ledges is used to reconcile the above exception with the theoretical predictions and to explain the inapplicability of the topographical theory in the case of dislocation etch pits. Results indicate that the onset of multilayer adsorption at the ledges of lithium fluoride occur for ferric ion concentrations of 5 to 10 ppm. The pit width rate variation as a function of lithium fluoride concentration is discussed. (C.J.G.)
- Research Organization:
- Carnegie Inst. of Tech., Pittsburgh. Metals Research Lab.
- NSA Number:
- NSA-14-008400
- OSTI ID:
- 4169578
- Report Number(s):
- NP-8351
- Country of Publication:
- United States
- Language:
- English
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