SELF-DIFFUSION OF OXYGEN IN SINGLE CRYSTAL AND POLYCRYSTALLINE ALUMINUM OXIDE

Journal Article · Mon Aug 01 04:00:00 EDT 1960 · Journal of Chemical Physics (U.S.)

DOI:https://doi.org/10.1063/1.1731170· OSTI ID:4168449

Oishi, Y; Kingery, W D

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)

• Research Organization: Massachusetts Inst. of Tech., Cambridge
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-022058
• OSTI ID: 4168449
• Journal Information: Journal of Chemical Physics (U.S.), Journal Name: Journal of Chemical Physics (U.S.) Vol. Vol: 33; ISSN JCPSA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALUMINUM OXIDES
CRYSTALS
DIFFUSION
EQUATIONS
GASES
HEAT TREATMENTS
HIGH TEMPERATURE
IMPURITIES
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
MONOCRYSTALS
OXYGEN
OXYGEN 18
QUANTITATIVE ANALYSIS
SAMPLING
SOLIDS
STABILITY
TESTING
THERMODYNAMICS
TRACER TECHNIQUES