Статья

EPR and Luminescence of ${\hbox {F}}^{+}$ Centers in Bulk and Nanophosphor Oxyorthosilicates

D. W. CookeLos Alamos National Laboratory, Los Alamos, NM, USAMichael W. BlairLos Alamos National Laboratory, Los Alamos, NM, USAJames F. SmithLos Alamos National Laboratory, Los Alamos, NM, USABryan BennettLos Alamos National Laboratory, Los Alamos, NM, USALuiz G. JacobsohnLos Alamos National Laboratory, Los Alamos, NM, USAEdward A. McKigneyLos Alamos National Laboratory, Los Alamos, NM, USAR. E. MuenchausenLos Alamos National Laboratory, Los Alamos, NM, USA

2008en

ABI

Аннотация

The main thermally stimulated luminescence glow peak in irradiated oxyorthosilicates occurs near 360-400 K and has been postulated to comprise an electron trapped at an oxygen vacancy (F + center). We have used electron paramagnetic resonance spectroscopy to identify this defect in Ln 2 SiO 5 :Ce (Ln = Lu and Y) and show that it consists of a single electron trapped at a non-silicon-bonded oxygen vacancy in both bulk and nanophosphor oxyorthosilicates. Both Lu- and Y-based nanophosphors form seven- and nine-oxygen coordinated structures (P2 1 /c) whereas the bulk phosphors form six- and seven-oxygen coordinated structures (C2/c). In each case the F + center predominately forms at the larger oxygen site. A typical resonance comprises a single Gaussian line broadened by hyperflne interaction with g-values near the free electron value and hyperflne coupling ~0.4 mT. The F + center can be annealed and radiation-induced, consistent with the thermally stimulated luminescence glow peak behavior.

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Идентификаторы

DOI: 10.1109/tns.2008.922798

Цитирования и источники

Цитирований: 3Использованных источников: 0

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