Photolytic and Reduction Coloring of CaWO4:Nd
| Autor: | M. W. Beaubien, D. C. Cronemeyer |
|---|---|
| Rok vydání: | 1964 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 35:1779-1785 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.1713741 |
| Popis: | Intense flash‐tube irradiation produces a brownish color in CaWO4:Nd, principally by absorption of wavelengths shorter than 300 mμ. Initially, the photolytic optical absorption has a peak near 3.0 eV for E∥c, and at 3.0 eV for E⊥c. At 300°K, there is a fast partial decay of the optical absorption within a few hours followed by a slow subsequent decay which stabilizes within a few days. On approach to equilibrium, the initial 3.0‐eV E∥c peak decomposes to two peaks at 2.5 and 3.0 eV. The absorption for E⊥c diminishes with time, but the peak remains near 3.0 eV. The absorption coefficient for E∥c in this photolytic case is always about twice that for E⊥c. The photolytic coloring is removed by heating at 300°C for a few hours. It is unaffected by compensation of Nd with Na. Reduction of lightly doped CaWO4:Nd induces an optical absorption which peaks at 2.5 eV for both E∥c and E⊥c. For heavily doped CaWO4:Nd:Na, absorption peaks at 2.2 eV for E⊥c and 2.2 and 2.9 eV for E∥c are produced. Thus, reduction and p... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|