Further Investigations of the Effect of Replacing Lithium by Sodium on Lithium Silicate Scintillating Glass Efficiency
Ce3+ doped lithium (6Li) silicate glasses are thermal neutron detectors. Prior work showed that when sodium (Na) is substituted for Li the scintillation efficiency, under beta particle stimulation, increased and then decreased as the sodium (Na) content was increased [1]. When all the 6Li was replaced by Na no scintillation was observed. Raman spectra, acquired using a visible excitation source provided no evidence of anomalous behavior. SEM microscopy did show some phase separation, but there was no obvious correlation with the scintillation efficiency. We have reexamined these glass samples using deep UV Raman excitation which reduces fluorescence interference. The newly acquired spectra show evidence of phase separation in the glasses. Specifically we see a peak at 800 cm-1 Raman shift which can be assigned to a vitreous silica moiety that results from phase separation. There is a strong correlation between this peak's area, the scintillation efficiency, and the Na content. The observed trend suggests that phase separation enhances scintillation and addition of Na reduces the amount of phase separation. We also see evidence of at least two defect structures that can be tentatively assigned to a three-membered ring structure and an oxygen vacancy. The latter is fairly strongly correlated with enhanced scintillation efficiency.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1037509
- Report Number(s):
- PNNL-SA-82921; TRN: US1201611
- Journal Information:
- Journal of Non-Crystalline Solids, Vol. 358, Issue 4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BETA PARTICLES
CERIUM ADDITIONS
DEFECTS
CRYSTAL DOPING
EFFICIENCY
EXCITATION
FLUORESCENCE
GLASS
LITHIUM
LITHIUM SILICATES
MICROSCOPY
OXYGEN
RAMAN SPECTRA
SCINTILLATIONS
SILICA
SILICATES
SODIUM
SPECTRA
STIMULATION
THERMAL NEUTRONS
Cerium- lithium-silicate glasses
Thermal neutron detector
Raman spectroscopy