DIFFUSION STUDIES IN CERAMIC CRYSTALS.
MCCRONE RESEARCH INST CHICAGO ILL
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The objectives of the present investigation have been the determination of the diffusion mechanisms operative in ceramic crystals having open structures. There is reason to believe that the diffusion mechanisms in such crystals are different from the vacancy or interstitial diffusion processes normally assumed in the case of closely packed metals, halides, and other crystals having similar dense structures. For example, a voidal diffusion mechanism was suggested to be operable in crystals having the relatively open wurtzite and sphalerite structures. It was also shown that diffusion should be anisotropic in such crystals and, based on the somewhat scanty experimental data then availabe, it was demonstrated that diffusion should be anisotropic in these crystals and, in fact, estimates were made of the magnitude of the anisotropic activation energies and found to be in agreement with published data. Thus a secondary objective of the present investigation has been the correlation of anisotropies in crystal structure to anisotropies in the diffusion processes.