Thumbnail
Access Restriction
Open

Author Oishi, Y. ♦ Kingery, W. D.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword METALS, CERAMICS, AND OTHER MATERIALS ♦ ALUMINUM OXIDES ♦ CRYSTALS ♦ DIFFUSION ♦ EQUATIONS ♦ GASES ♦ HEAT TREATMENTS ♦ HIGH TEMPERATURE ♦ IMPURITIES ♦ MEASURED VALUES ♦ MONOCRYSTALS ♦ OXYGEN ♦ OXYGEN 18 ♦ QUANTITATIVE ANALYSIS ♦ SAMPLING ♦ SOLIDS ♦ STABILITY ♦ TESTING ♦ THERMODYNAMICS ♦ TRACER TECHNIQUES
Abstract The self-diffusion coefflcient of oxygen was determined as a function of temperature in single-crystal and polycrystaline aluminum oxide at temperatures up to 1780 deg C. The rate of exchange between a gas phase and solid particles was measured, utilizing the stable isotope O/sup 18/ In single crystals of aluminum oxide intrinsic diffusion occurs in a high-temperature region, depending on temperature as D = 1.9 x 10/sup 3/ exp(-152,000/RT). At temperatures below about 1600 deg C variable results were obtained depending on impurity content and previous heat treatment. For one set of samples experimental results could be represented as D = 6.3 x 10/sup -8/ exp(-57,600/RT). The diffusion coefficient of oxygen in polycrystalline samples is about two orders of magnitude larger than tbat found for the single crysthls, and has a somewhat smaller activation energy. With the polycrystalline oxide, variable results were also observed at lower temperatures. (auth)
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1960-08-01
Publisher Department Massachusetts Inst. of Tech., Cambridge
Journal Journal of Chemical Physics
Volume Number 33
Organization Massachusetts Inst. of Tech., Cambridge


Open content in new tab

   Open content in new tab