Electron nuclear double resonance study of photostimulated luminescence active centers in CsBr:Eu2+ medical imaging plates
Electron nuclear double resonance study of photostimulated luminescence active centers in CsBr:Eu2+ medical imaging plates
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CsBr:Eu2 医学成像板光激发光活性中心的电子核双共振研究
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
F. Callens
中科院分区：
文献类型：
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作者：
H. Vrielinck;F. Loncke;J. Tahon;P. Leblans;P. Matthys;F. Callens
CsBr：Eu{sup 2+}针像板在室温下具有电子顺磁共振（EPR）谱，其强度与板的光激励发光灵敏度有关。该EPR谱表现出很强的温度依赖性：在室温下，它是由于一个单一的Eu{sup 2+}（S =7/2）中心与轴对称，而在T<35 K的光谱只能解释时，假设存在两个不同的中心，少数轴中心和多数中心几乎极端菱形对称。本文用电子核双共振（ENDOR）谱研究了这些低温中心，发现中心Eu{sup 2+}离子附近存在{sup 1}H核。ENDOR光谱的角度依赖性的分析允许提出这些中心的模型，提供了一个解释的光谱分量之间的强度和它们的温度依赖性的观察到的差异。
CsBr:Eu{sup 2+} needle image plates exhibit an electron-paramagnetic-resonance (EPR) spectrum at room temperature (RT), whose intensity is correlated with the photostimulated luminescence sensitivity of the plate. This EPR spectrum shows a strong temperature dependence: At RT it is owing to a single Eu{sup 2+} (S =7/2) center with axial symmetry, whereas at T<35 K the spectra can only be explained when two distinct centers are assumed to be present, a minority axial center and a majority center with nearly extremely rhombic symmetry. In this paper these low-temperature centers are studied with electron nuclear double resonance (ENDOR) spectroscopy, which reveals the presence of {sup 1}H nuclei close to the central Eu{sup 2+} ions in the centers. Analysis of the angular dependence of the ENDOR spectra allows to propose models for these centers, providing an explanation for the observed difference in intensity between the spectral components and for their temperature dependence.