Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions
Lutetium oxyorthosilicate Lu<sub>2</sub>SiO<sub>5</sub> (LSO) and pyrosilicate Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> (LPS) activated by Ce<sup>3+</sup> or Pr<sup>3+</sup> are known to be effective and fast scinti...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-06-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/16/12/4488 |
| _version_ | 1797593658772422656 |
|---|---|
| author | Valentyn Laguta Lubomir Havlak Vladimir Babin Jan Barta Jan Pejchal Martin Nikl |
| author_facet | Valentyn Laguta Lubomir Havlak Vladimir Babin Jan Barta Jan Pejchal Martin Nikl |
| author_sort | Valentyn Laguta |
| collection | DOAJ |
| description | Lutetium oxyorthosilicate Lu<sub>2</sub>SiO<sub>5</sub> (LSO) and pyrosilicate Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> (LPS) activated by Ce<sup>3+</sup> or Pr<sup>3+</sup> are known to be effective and fast scintillation materials for the detection of X-rays and γ-rays. Their performances can be further improved by co-doping with aliovalent ions. Herein, we investigate the Ce<sup>3+</sup>(Pr<sup>3+</sup>) → Ce<sup>4+</sup>(Pr<sup>4+</sup>) conversion and the formation of lattice defects stimulated by co-doping with Ca<sup>2+</sup> and Al<sup>3+</sup> in LSO and LPS powders prepared by the solid-state reaction process. The materials were studied by electron paramagnetic resonance (EPR), radioluminescence spectroscopy, and thermally stimulated luminescence (TSL), and scintillation decays were measured. EPR measurements of both LSO:Ce and LPS:Ce showed effective Ce<sup>3+</sup> → Ce<sup>4+</sup> conversions stimulated by Ca<sup>2+</sup> co-doping, while the effect of Al<sup>3+</sup> co-doping was less effective. In Pr-doped LSO and LPS, a similar Pr<sup>3+</sup> → Pr<sup>4+</sup> conversion was not detected by EPR, suggesting that the charge compensation of Al<sup>3+</sup> and Ca<sup>2+</sup> ions is realized via other impurities and/or lattice defects. X-ray irradiation of LPS creates hole centers attributed to a hole trapped in an oxygen ion in the neighborhood of Al<sup>3+</sup> and Ca<sup>2+</sup>. These hole centers contribute to an intense TSL glow peak at 450–470 K. In contrast to LPS, only weak TSL peaks are detected in LSO and no hole centers are visible via EPR. The scintillation decay curves of both LSO and LPS show a bi-exponential decay with fast and slow component decay times of 10–13 ns and 30–36 ns, respectively. The decay time of the fast component shows a small (6–8%) decrease due to co-doping. |
| first_indexed | 2024-03-11T02:12:33Z |
| format | Article |
| id | doaj.art-856559e4d90b49848ab69dd4faa34176 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T02:12:33Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-856559e4d90b49848ab69dd4faa341762023-11-18T11:27:00ZengMDPI AGMaterials1996-19442023-06-011612448810.3390/ma16124488Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> IonsValentyn Laguta0Lubomir Havlak1Vladimir Babin2Jan Barta3Jan Pejchal4Martin Nikl5Institute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Cukrovarnicka 10/112, 16200 Prague, Czech RepublicLutetium oxyorthosilicate Lu<sub>2</sub>SiO<sub>5</sub> (LSO) and pyrosilicate Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> (LPS) activated by Ce<sup>3+</sup> or Pr<sup>3+</sup> are known to be effective and fast scintillation materials for the detection of X-rays and γ-rays. Their performances can be further improved by co-doping with aliovalent ions. Herein, we investigate the Ce<sup>3+</sup>(Pr<sup>3+</sup>) → Ce<sup>4+</sup>(Pr<sup>4+</sup>) conversion and the formation of lattice defects stimulated by co-doping with Ca<sup>2+</sup> and Al<sup>3+</sup> in LSO and LPS powders prepared by the solid-state reaction process. The materials were studied by electron paramagnetic resonance (EPR), radioluminescence spectroscopy, and thermally stimulated luminescence (TSL), and scintillation decays were measured. EPR measurements of both LSO:Ce and LPS:Ce showed effective Ce<sup>3+</sup> → Ce<sup>4+</sup> conversions stimulated by Ca<sup>2+</sup> co-doping, while the effect of Al<sup>3+</sup> co-doping was less effective. In Pr-doped LSO and LPS, a similar Pr<sup>3+</sup> → Pr<sup>4+</sup> conversion was not detected by EPR, suggesting that the charge compensation of Al<sup>3+</sup> and Ca<sup>2+</sup> ions is realized via other impurities and/or lattice defects. X-ray irradiation of LPS creates hole centers attributed to a hole trapped in an oxygen ion in the neighborhood of Al<sup>3+</sup> and Ca<sup>2+</sup>. These hole centers contribute to an intense TSL glow peak at 450–470 K. In contrast to LPS, only weak TSL peaks are detected in LSO and no hole centers are visible via EPR. The scintillation decay curves of both LSO and LPS show a bi-exponential decay with fast and slow component decay times of 10–13 ns and 30–36 ns, respectively. The decay time of the fast component shows a small (6–8%) decrease due to co-doping.https://www.mdpi.com/1996-1944/16/12/4488scintillation materialluminescenceEPRlattice defectradioluminescence |
| spellingShingle | Valentyn Laguta Lubomir Havlak Vladimir Babin Jan Barta Jan Pejchal Martin Nikl Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions Materials scintillation material luminescence EPR lattice defect radioluminescence |
| title | Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions |
| title_full | Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions |
| title_fullStr | Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions |
| title_full_unstemmed | Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions |
| title_short | Charge Transfer and Charge Trapping Processes in Ca- or Al-Co-doped Lu<sub>2</sub>SiO<sub>5</sub> and Lu<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> Scintillators Activated by Pr<sup>3+</sup> or Ce<sup>3+</sup> Ions |
| title_sort | charge transfer and charge trapping processes in ca or al co doped lu sub 2 sub sio sub 5 sub and lu sub 2 sub si sub 2 sub o sub 7 sub scintillators activated by pr sup 3 sup or ce sup 3 sup ions |
| topic | scintillation material luminescence EPR lattice defect radioluminescence |
| url | https://www.mdpi.com/1996-1944/16/12/4488 |
| work_keys_str_mv | AT valentynlaguta chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions AT lubomirhavlak chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions AT vladimirbabin chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions AT janbarta chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions AT janpejchal chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions AT martinnikl chargetransferandchargetrappingprocessesincaoralcodopedlusub2subsiosub5subandlusub2subsisub2subosub7subscintillatorsactivatedbyprsup3suporcesup3supions |