Radio-photoluminescence Properties of Eu-doped CaBPO5

Sensors and Materials

Published On 2024

Eu-doped CaBPO5 was synthesized by the solid-state reaction route, and then its radiophotoluminescence properties were studied. On the basis of steady-state and time-resolved photoluminescence (PL) studies, it was confirmed that Eu2+ is formed by X-ray irradiation due to the valence change of the Eu ion (Eu3+→ Eu2+). In addition, for dosimetric applications, it was demonstrated that the PL intensity of Eu2+ is proportional to the accumulated radiation dose, is stable after irradiation, and can be reversed by heat treatment at 500℃ for 100 s.

Journal

Sensors and Materials

Published On

2024

Volume

36

Issue

2

Page

559-564

Authors

Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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H-Index(all)

44

H-Index(since 2020)

19

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

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0

Research Interests

Odor sensor

Dosimeter

Thin films

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Hidehito Nanto

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Kanazawa Institute of Technology

Journal of Alloys and Compounds

Radiophotoluminescence properties of Bi-doped NaCaBO3

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Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Sensors and Materials

Radio-photoluminescence Properties of Eu-doped CaBPO5

Eu-doped CaBPO5 was synthesized by the solid-state reaction route, and then its radiophotoluminescence properties were studied. On the basis of steady-state and time-resolved photoluminescence (PL) studies, it was confirmed that Eu2+ is formed by X-ray irradiation due to the valence change of the Eu ion (Eu3+→ Eu2+). In addition, for dosimetric applications, it was demonstrated that the PL intensity of Eu2+ is proportional to the accumulated radiation dose, is stable after irradiation, and can be reversed by heat treatment at 500℃ for 100 s.

Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Japanese Journal of Applied Physics

Radiophotoluminescence properties of Eu-doped Li2SrSiO4 for radiation detectors

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2023/12/20

Article Details
Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Journal of Materials Science: Materials in Electronics

ESR studies to elucidate the origin of the RPL emission of undoped-CaSO4

Recent research has shown that CaSO4, without any intentional addition of impurities, exhibits remarkable radiophotoluminescence (RPL) properties. However, the origin of the RPL in CaSO4 has yet to be fully understood. ESR measurements were carried out to identify the defect species responsible for RPL and elucidate the luminescence’s origin. ESR measurements on undoped-CaSO4 with different radiation sensitivities showed SO4−, SO2−+SO3−, PO42−, Si=O3 in P2O5–SiO2 (E’ center), Al2O3 hole center and Mn2+ defect species in CaSO4. This means that CaSO4 contains Al2O3, Mn2+, P, and Si as impurities, which are not intentionally added to CaSO4. As the results of this study, the different impurity states may influence the radiation sensitivity of the materials. It is suggested that the deliberate addition of P and Si elements, Al2O3 and Mn2+ could control the RPL properties.

Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

Materials Research Bulletin

X-ray induced reduction of Sm3+ into Sm2+ in Li2CaSiO4 and its potential for radiation measurement applications

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Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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2022/11/22

Article Details
Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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2022/11/21

Article Details
Hidehito Nanto

Hidehito Nanto

Kanazawa Institute of Technology

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Sensors and Materials

Optimal Ground Control Point Utilization for Aligning 3D Surface Models of Forest Areas with Steep Slopes

Unmanned aerial vehicles (UAVs) have been used to survey forests for decades. To monitor post-forest operation effects such as the surface deformation of forest soils (eg, soil erosion and deposition), the alignment of 3D surface models using ground control points (GCPs) by georeferencing is necessary. However, the GCP network optimization for surveying forests has not been clearly established. We installed 29 GCPs on tree stumps in a post-timber harvesting site to spatially correct UAV survey results, for which real-time kinematics data were unavailable. The GCPs for georeferencing were randomly selected from 13 validation sets for each of the three trials in this study; the GCP and checkpoint root mean square errors (RMSEs) were used for determining the georeferencing results. Even if the number of GCPs increased, the GCP RMSE did not decrease; the checkpoint RMSE decreased by 2.03 cm. The 3D …

somyot kaitwanidvilai

somyot kaitwanidvilai

King Mongkut's Institute of Technology Ladkrabang

Sensors and Materials

Dual-stage Classification Framework for Detecting Rare or Unseen Patterns Based on Novelty Detection and Supervised Learning

In this article, we propose a dual-stage classification framework designed for identifying rare or unseen patterns in the hard disk drive (HDD) industrial test process. The proposed framework integrates novelty detection and supervised learning methodologies to effectively address the challenges associated with imbalanced datasets and the detection of infrequent or unseen patterns within continuously changing environments. By employing novelty detection as the first-stage classifier followed by supervised learning as the second-stage classifier, the proposed method demonstrates an increased capacity to adapt to fluctuating environments, consequently enhancing the overall accuracy of process classification in practical manufacturing settings. To strengthen the robustness of novelty detection methods, an ensemble model technique is employed. Notably, the accuracy of the novelty detection methods in the first …

Daisuke Nakauchi

Daisuke Nakauchi

Nara Institute of Science and Technology

Sensors and Materials

Scintillation Properties of Eu-doped KI Single Crystals

The photoluminescence and scintillation properties of KI: Eu synthesized by the vertical Bridgman–Stockbarger method were investigated. All the samples showed a broad peak at 430–450 nm under UV and X-ray irradiations, and the origin of emission was ascribed to the 4f65d1–4f7 transition of Eu2+. Furthermore, a tail emission at 500 nm under X-ray irradiation was observed, the origin of which could be ascribed to color centers associated with oxygen impurities. According to the pulse height spectra, the highest light yield (LY) under 241Am γ-ray (60 keV) irradiation was 3400 photons/MeV among the prepared samples. In terms of LY and afterglow, the optimal concentration of Eu was found to be 0.3%.

Daisuke Nakauchi

Daisuke Nakauchi

Nara Institute of Science and Technology

Sensors and Materials

Scintillation Properties of Rb2Cu (Cl, Br) 3 Crystals

Rb2Cu (Cl, Br) 3 crystals were synthesized by the slow cooling method and their photoluminescence (PL) and scintillation properties were evaluated. PL emission peaks at 390 nm due to the recombination of excitons were observed, and the PL quantum yields of Rb2CuCl3, Rb2Cu (Cl0. 5, Br0. 5) 3, and Rb2CuBr3 were 91.2, 95.3, and 96.3%, respectively. PL decay curves were approximated using a single exponential function model, and the obtained decay time constants were 15–66 μs. Under X-ray irradiation, the scintillation emission peaks of the samples were observed at 390 nm, and the decay times were 11–63 μs. The afterglow levels at 20 ms after X-ray irradiation were calculated to be 30–450 ppm. Rb2CuCl3 showed the highest scintillation light yield of 11000 photons/MeV among the samples when calculated from the pulse height spectra of 137Cs γ-rays (662 keV).

Yoshimichi Yamamoto

Yoshimichi Yamamoto

Tokai University

Sensors and Materials

Optimal Prediction of Effectiveness of Mangrove Forest Against Coastal Erosion: Case Study of Coastal Area along the Gulf of Thailand

Many types of solid breakwaters are used to prevent coastal erosion in Thailand. Most breakwaters require a large budget to construct, and concrete breakwaters are not suitable for the clay coasts of Thailand. These solid breakwaters interfere with the lives of people living along the coast and are a common source of complaint. The Department of Marine and Coastal Resources in Thailand is taking a serious look at the study of mangrove forests. Mangrove forests are a natural dam that is suitable, reasonable, and sustainable for Thailand and can be planted easily with low budget. For example, fishermen can pass through mangrove forests in small boats, and some of the roots of mangroves can be removed to provide a passage to the sea; these roots can regrow to support the mangrove trunk. The mature seeds of mangroves fall into the mud, enabling the growth of further trees. The roots of mangrove trees act as a …

Daisuke Nakauchi

Daisuke Nakauchi

Nara Institute of Science and Technology

Sensors and Materials

Scintillation Properties of Tb4O7–Al2O3 Glasses

Undoped and Ce-doped Tb4O7–Al2O3 glasses without glass network-former oxides were synthesized by the containerless method. The X-ray diffraction measurement indicated that the synthesized glass samples were amorphous. In diffuse transmission spectra, the undoped sample showed absorption due to Tb4+, and the reduction of Tb4+ to Tb3+ was observed in Ce-doped samples. In X-ray-induced scintillation spectra, the Ce-doped samples showed luminescence due to the 4f-4f transitions of Tb3+. This result indicated that CeCl3 acted as a reducer and enhanced the luminescence due to Tb3+. In addition, the Ce-doped samples suppressed the thermally stimulated luminescence glow peaks at the low-temperature region.