Charge and mass transfer involving hydrogen in MgO crystals thermochemically reduced at high temperatures
Abstract
Optical-absorption measurements show that H- ions are thermally much more stable than anion vacancies when thermochemically reduced MgO samples are annealed in a reducing atmosphere. At 1900 K all anion vacancies are annihilated, but the concentration of H- ions remains unchanged. Results of electron irradiations on a crystal annealed at 1900 K demonstrate unambiguously that the infrared-absorption peaks previously attributed to H- ions are indeed due to protons in anion sublattice sites. H- concentrations can be obtained from the infrared absorbance of the H- ions. The lifetime of the 2.3-eV F-center phosphorescence is shown to be affected by the relative concentrations of H- ions to anion vacancy. Decreasing the anion-vacancy concentration by thermal annealing, thereby increasing the relative concentration of H- ions to anion vacancies, leads to an enhancement of the lifetime of the phosphorescence.
- Publication:
-
Physical Review B
- Pub Date:
- January 1983
- DOI:
- 10.1103/PhysRevB.27.1276
- Bibcode:
- 1983PhRvB..27.1276C