Secondary ion mass spectrometric analysis of oxygen self-diffusion in single-crystal MgO
Single-crystal layers of Mg/sup 18/O were grown epitaxially on substrates of normal MgO through chemical transport with HCl. Exchange between /sup 18/O in the crystals and the /sup 16/O present in air was produced by annealings in the temperature range of 1000-1650/sup 0/C, and diffusion coefficients were detemined from concentration gradients measured with the aid of secondary ion mass spectrometry. The temperature dependence of the oxygen self-diffusion coefficients so obtained may be represented by an activation energy of 3.24 +/- 0.13 eV and D/sub 0/ of (1.8/sub -1.1//sup +2.9/) x 10/sup -6/ cm/sup 2//s. The magnitude of the diffusivities is lower than that first obtained by exchange measurements but agrees well with recent values obtained from gradients established through proton activation analysis. The present activation energy is in the middle of the range reported in previous studies. This value is too large to represent an enthalpy for anion vacancy migration and is far too small to represent the combination of defect migration and formation enthalpies to be expected if, as presently believed, the defect structure of MgO were dominated by cation impurities. 22 references, 5 figures, 1 table.
- Research Organization:
- Massachusetts Institute of Technology, Cambridge
- DOE Contract Number:
- AC02-76ER01198
- OSTI ID:
- 6952173
- Journal Information:
- Adv. Ceram.; (United States), Vol. 10
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxygen diffusion in hypostoichiometric uranium dioxide
Radiation enhanced diffusion in MgO
Related Subjects
MAGNESIUM OXIDES
SELF-DIFFUSION
ACTIVATION ENERGY
CRYSTAL DEFECTS
EXPERIMENTAL DATA
MASS SPECTROSCOPY
OXYGEN 18
TRACER TECHNIQUES
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CRYSTAL STRUCTURE
DATA
DIFFUSION
ENERGY
EVEN-EVEN NUCLEI
INFORMATION
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAGNESIUM COMPOUNDS
NUCLEI
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
SPECTROSCOPY
STABLE ISOTOPES
360603* - Materials- Properties