Ion-probe measurement of oxygen self-diffusion in single-crystal Al/sub 2/O/sub 3/

Journal Article · Tue Jan 01 04:00:00 EST 1980 · J. Am. Ceram. Soc.; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1980.tb10655.x· OSTI ID:5572526

Reed, D J; Wuensch, B J

Anion self-diffusion coefficients normal to (1 anti 102) were obtained for single-crystal Al/sub 2/O/sub 3/ in a 1.3 x 10/sup -3/ N/m/sup 2/ (10/sup -5/ torr) vacuum at 1585/sup 0/ to 1840/sup 0/C. Tracer was supplied from an initial 650 to 1300 A Al/sub 2//sup 18/O/sub 3/ layer produced by the oxidation of vapor-deposited Al metal films in an /sup 18/O/sub 2/ atmosphere at 520/sup 0/C. Concentration gradients extended over depths of 3000 to 5000 A and were measured by mass spectrometry of material sputtered from the samples with a beam of Ar/sup +/ ions. Crystals which had not been preannealed to remove surface damage displayed enhanced diffusion. Diffusion coefficients from preannealed crystals may be described by D/sub -0/ = 6.4 x 10/sup 5/ cm/sup 2//s, with an activation energy of 188 +- 7 kcal/mol. The diffusion is interpreted as an extrinsic vacancy mechanism.

• Research Organization: Massachusetts Inst. of Technology, Cambridge
• OSTI ID: 5572526
• Journal Information: J. Am. Ceram. Soc.; (United States), Journal Name: J. Am. Ceram. Soc.; (United States) Vol. 63:1-2; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANNEALING
CHALCOGENIDES
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
CRYSTALS
DAMAGE
DIFFUSION
ELEMENTS
ENTHALPY
EVEN-EVEN NUCLEI
FLUIDS
HEAT TREATMENTS
ISOTOPES
LIGHT NUCLEI
MONOCRYSTALS
NONMETALS
NUCLEI
OXIDATION
OXIDES
OXYGEN
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PHYSICAL PROPERTIES
SELF-DIFFUSION
SORPTIVE PROPERTIES
STABLE ISOTOPES
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION HEAT
VAPORIZATION HEAT