| Autor: |
R. Gonzalez, O. E. Schow, G. P. Summers, Y. Chen |
| Rok vydání: |
1983 |
| Předmět: |
|
| Zdroj: |
Physical Review B. 27:1276-1282 |
| ISSN: |
0163-1829 |
| DOI: |
10.1103/physrevb.27.1276 |
| Popis: |
Optical-absorption measurements show that ${\mathrm{H}}^{\ensuremath{-}}$ 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 ${\mathrm{H}}^{\ensuremath{-}}$ ions remains unchanged. Results of electron irradiations on a crystal annealed at 1900 K demonstrate unambiguously that the infrared-absorption peaks previously attributed to ${\mathrm{H}}^{\ensuremath{-}}$ ions are indeed due to protons in anion sublattice sites. ${\mathrm{H}}^{\ensuremath{-}}$ concentrations can be obtained from the infrared absorbance of the ${\mathrm{H}}^{\ensuremath{-}}$ ions. The lifetime of the 2.3-eV $F$-center phosphorescence is shown to be affected by the relative concentrations of ${\mathrm{H}}^{\ensuremath{-}}$ ions to anion vacancy. Decreasing the anion-vacancy concentration by thermal annealing, thereby increasing the relative concentration of ${\mathrm{H}}^{\ensuremath{-}}$ ions to anion vacancies, leads to an enhancement of the lifetime of the phosphorescence. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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