Abstract
β: CaSiO3 polycrystal was synthesized by the devitrification method. The polycrystal exhibits three thermoluminescence (TL) peaks at 124 °C, 250 °C and 306 °C. Electron paramagnetic resonance (EPR) spectroscopy was used to study the defect centers induced in the polycrystal by gamma irradiation and to identify the centers responsible for the TL process. Three defect centers contribute to the observed spectrum at room temperature. Center I with principal g-values 2.0135, 2.0094 and 2.0038 is attributed to O− ion and the center appears to be the recombination center for 124 °C, 147 °C and 306 C TL peaks. Center II exhibiting an isotropic g-value of 2.00025 is identified as an F+-center (singly ionized oxygen vacancy). F+-center is also observed to be a recombination center for several TL peaks. Center III is assigned to a Ti3+ center displaying an orthorhombic g-tensor with principal values g1 = 1.9830, g2 = 1.9741 and g3 = 1.9046. This center is associated with 124 °C and 147 °C TL peaks. TL emission spectrum of β-CaSiO3 shows two emission bands at 370 and 520 nm.
Original language | English |
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Article number | 116783 |
Journal | Journal of Luminescence |
Volume | 217 |
DOIs | |
State | Published - Jan 2020 |
Bibliographical note
Funding Information:The authors wish to thank Ms. E. Somessari and Mr. Aldo Oliveira, Institute for Energy and Nuclear Researches (IPEN), Brazil, for kindly carrying out the irradiation of the samples. To FAPESP (Process number 2014/03085-0) for partial financial support and to CNPq for fellowship to C.D. Gonzales-Lorenzo (Process number 162741/2015-4).
Funding Information:
The authors wish to thank Ms. E. Somessari and Mr. Aldo Oliveira, Institute for Energy and Nuclear Researches (IPEN), Brazil, for kindly carrying out the irradiation of the samples. To FAP ESP (Process number 2014/03085-0) for partial financial support and to CNPq for fellowship to C.D. Gonzales-Lorenzo (Process number 162741/2015-4).
Publisher Copyright:
© 2019 Elsevier B.V.
Keywords
- CaSiO
- Defects centers
- EPR
- TL