Diffusion of Beryllium in Beryllium Oxide: Part II

Technical Report · Mon May 01 04:00:00 EDT 1961

DOI:https://doi.org/10.2172/4012730· OSTI ID:4012730

Austerman, S. B. ^[1]

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1. North American Aviation, Inc., Canoga Park, CA (United States). Atomics International Div.

The diffusion coefficient for Be in BeO was measured as a function of temperature for a group of identical polycrystalline BeO samples, as well as in a variety of types of BeO samples. The temperature dependence follows two straight lines on a log D--l/T graph, the lines intersecting at 1725 °C. The lines correspond to the equations: D = 1.37 exp$$(-\frac{91.9 kcal/mole}{RT})$$ (1550 °C to 1725 °C), and D = 1.10 x 10^-6 exp$$(-\frac{36.15 kcal/mole}{RT})$$ (1725 °C to 2000 °C). The diffusion coefficient at 1800 °C for this particular set of samples is approx. 40 times less than that for a different type of BeO, as previously published. The significance of certain material parameters is considered; no correlation is noted between the magnitude of the diffusion coefficient and any single parameter. The observed wide variations in D (a maximum of 40x at 1800 °C) are probably the net result of simultaneous changes in many of the significance parameters of the polycrystalline samples. Lattice diffusion the inferred principal mode of diffusion in all cases.

• Research Organization: North American Aviation, Inc., Canoga Park, CA (United States). Atomics International Div.
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: AT(11-1)-GEN-8
• NSA Number: NSA-15-018494
• OSTI ID: 4012730
• Report Number(s): NAA-SR--5893
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BERYLLIUM
BERYLLIUM OXIDES
CRYSTALS
DIAGRAMS
DIFFUSION
EQUATIONS
HIGH TEMPERATURE
LATTICES
MEASURED VALUES
SAMPLING
TEMPERATURE
VARIATIONS