Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1816286 | Physica B: Condensed Matter | 2006 | 4 Pages |
Absorption, fluorescence and thermoluminescence spectra are presented for 1.5-MeV neutron-irradiated YAG crystals grown by Czochralski (CZ) and temperature gradient technique (TGT). F+ centers were formed in both YAG samples and valence of iron impurities in TGT-grown YAG crystals switched from divalent to trivalent after neutron irradiation. At 350 and 300 °C thermoluminescence was observed in CZ-grown and TGT-grown YAG crystals, respectively, and assigned to irradiation-induced color centers. Calculated with the initial elevation method, thermoluminescence trap depths of the 350 °C band and of the 300 °C band are 0.379 and 0.768 eV, respectively. The significant difference in thermoluminescence intensities between CZ- and TGT-grown YAG crystals is associated with the irradiation-induced color centers and quenching effect of Fe3+ ions.