Dissolution Kinetics at Dislocation Etch Pits in Single Crystals of Lithium Fluoride

Abstract

The kinetics of dissolution at dislocation etch pits on lithium fluoride in dilute aqueous solutions of ferric fluoride were studied by interferometric observations on etched surfaces. The effects on dissolution of the variables time, temperature, undersaturation, crystal perfection, and crystal orientation were determined. It was found that dissolution was consistent with the mechanistic theories of crystal dissolution involving dissociation of lithium fluoride from monomolecular ledges on close-packed surfaces and subsequent diffusion into solution, if a time-dependent adsorption of inhibitor at the receding ledges is invoked.