ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Long lasting phosphorescence (LLP) and photostimulated luminescence (PSL) were found in reduced calcium aluminate glasses activated with Tb3+ ions. The LLP from Tb3+ was observed by illuminating the Tb3+ 4f→5d charge transfer band with ultraviolet (UV) 254 nm light, while the PSL was seen by stimulating the UV-illuminated glasses with 633 nm light. The decay curve of the LLP was fitted with a second-order kinetic for the initial period (0〈t〈20 min) and a first-order kinetic for the later (t〉30 min). An electron paramagnetic resonance (EPR) signal, which is attributed to an F+-like center associated with Ca2+ ions, was induced by illumination with UV light and its intensity decay was fitted with a first-order kinetic similarly to the later stage of the LLP. The appearance of the PSL by illumination is accompanied by a distinct intensity reduction of the EPR signal due to the F+-like center. The thermoluminescence spectra of the specimen illuminated with UV light at 77 K consist of two components peaking at ∼240 and ∼390 K. The low temperature component and the high temperature component were attributed to an F-like center and an F+-like center, respectively. These results lead to a conclusion that electrons of the F-like center and the F+-like center contribute predominantly to the emergence of the LLP and the PSL, respectively. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.371243
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