Research Achievements - Original paper -

Radiation response characteristics of Pr3+-activated SrO-Al2O3-TeO2 glasse

R. Nakamori, A. Takaku, N. Kawano, D. Onoda, Y. Takebuchi, H. Fukushima, T. Kato, K. Shinozaki, T. Yanagida

Sensors and Materials   34   707 - 716   2022.02  [Refereed]

Research paper (journal)   Domestic Co-author

Preparation and scintillation properties of the Eu3+-activated SrO–Al2O3–TeO2 glasses

R. Nakamori, N. Kawano, A. Takaku, D. Nakauchi, H. Kimura, M. Akatsuka, K. Shinozaki, T. Yanagida

Materials Research Bulletin   145   111547   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Optical, scintillation and thermoluminescent properties of Eu2O3-doped K2O–La2O3–Ga2O3 glasses

N. Kawano, K. Shinozaki, D. Nakauchi, H. Kimura, M. Akatsuka, T. Yanagida

Radiation physics and chemistry   190   109785   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Photoluminescence and scintillation characteristics of organic–inorganic layered perovskite-type compounds with a methoxyphenethylamine

N. Kawano, D. Nakauchi, M. Akatsuka, H. Kimura, T. Yanagida

Journal of Luminescence   241   118467   2022.01  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Radiation response characteristics of organic-inorganic perovskite-type compounds with a chlorophenetylamine

N. Kawano, A. Horimoto, H. Kimura, D. Nakauchi, M. Akatsuka, T. Yanagida

Materials Research Bulletin   142   111409   2021.10  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Development of (C6H5C2H4NH3)2Pb1-xCdxBr4 crystal scintillators with two-dimensional quantum-well structures

D. Onoda, M. Akatsuka, N. Kawano, D. Nakauchi, T. Kato, N. Kawaguchi, T. Yanagida

Journal of Luminescence   237   118157   2021.09  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Effects of Excitation Density on the Scintillation Properties of Organic-Inorganic Layered Perovskite-type Compounds

M. Koshimizu, N. Kawano, A. Kimura, S. Kurashima, M. Taguchi, Y. Fujimoto, and K. Asai

Sensors and Materials     2021.06  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of (C6H5C2H4NH3)2Pb1-xSnxBr4 crystals having two-dimensional quantum-well structures

Daichi Onoda, Masaki Akatsuka, Naoki Kawano, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi, Takayuki Yanagida

Optical Materials   114   111002   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Optical and radiation response characteristics of Eu2O3-doped K2O–Bi2O3–Ga2O3 glasses

Naoki Kawano, Kenji Shinozaki, Masaki Akatsuka, Hiromi Kimura, Daisuke Nakauchi, Takayuki Yanagida

Ceramics International   47   11596 - 11601   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Photoluminescence, scintillation and thermoluminescent properties of Tb-doped BaCaBO3F

S. Koide, N. Kawano, M. Akatsuka, H. Kimura, D. Nakauchi, G. Okada, T. Yanagida

Radiation Measurements   143   106563   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and thermoluminescent properties of Dy-doped calcium borate chloride

Naoki Kawano, Hiromi Kimura, Masaki Akatsuka, Daisuke Nakauchi, Go Okada, Takayuki Yanagida

Optical Materials   112   110784   2021.02  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Rapid Synthesis of Quantum-Sized Organic–Inorganic Perovskite Nanocrystals in Glass

Kenji Shinozaki, Naoki Kawano

Scientific Reports ( Scientific Reports )  10 ( 1 )   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, The Author(s). A bulk sample of an organic–inorganic (OI) perovskite crystal of (C6H5C2H4NH3)2PbBr4 with a layered structure showing excellent luminescent properties was rapidly synthesised. The raw materials of OI crystal were impregnated into nanoporous glass having 4-nm pores and dried, obtaining a translucent sample of OI nanocrystals in glass (OIiG). An absorbance shoulder was observed at E = 3.04 eV for OIiG, which was attributed to exciton bands, and photoluminescence (PL) duration times of τ1 = 2.8 ns and τ2 = 8.6 ns were recorded for OIiG. In contrast, for a single-crystal sample, E = 2.94 eV, τ1 = 4.1 ns, τ2 = 11.0 ns. Compared to those of the single-crystal sample, the OIiG has a higher absorbance energy, and the duration time was shorter. The exciton activation energy was 195 meV for OIiG, in contrast with 121 meV for single crystal. We propose that these changes are due to the size effect because the particle size (3–4 nm in diameter) in the OIiG is close to the Bohr radius of layer-structured OI crystals.

DOI PubMed

Radiation response properties of Dy-doped B2O3–Al2O3–SrO glasses

Naoki Kawano, Noriaki Kawaguchi, Go Okada, Yutaka Fujimoto, Takayuki Yanagida

Optik   224   165613   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of Dy-doped TeO2-Al2O3-BaO glasses

Akito TAKAKU, Naoki KAWANO, Hiromi KIMURA, Daisuke NAKAUCHI, Masaki AKATSUKA, Kenji SHINOZAKI, Takayuki YANAGIDA

Journal of the Ceramic Society of Japan   128   1024 - 1029   2020.12  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and TSL properties of Eu-doped BaCaBO<inf>3</inf>F

Naoki Kawano, Go Okada, Hiromi Kimura, Takayuki Yanagida

Ceramics International ( Ceramics International )  46 ( 16 ) 26339 - 26345   2020.11  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020 Elsevier Ltd and Techna Group S.r.l. We investigated photoluminescence (PL), scintillation and thermally-stimulated luminescence (TSL) properties of BaCaBO3F doped with different concentrations of Eu (0, 0.1, 1.0, and 10.0%) to develop phosphor materials for radiation measurement. The Eu-doped samples showed emissions with several sharp peaks due to the 4f-4f transitions of Eu3+ in PL and scintillation while no emission peak was observed in the undoped sample. The decay time constants of the Eu-doped samples in PL and scintillation were about 1.16–1.20 ms and 0.75–1.10 ms, respectively. In addition, the Eu-doped samples showed TSL due to the 4f-4f transitions of Eu3+. The thermal activation energies of the Eu-doped samples were calculated by TSL isothermal analysis, and the analysis suggested that eleven trapping centers with different activation energies involved in TSL might exist in the Eu-doped samples.

DOI

Photoluminescence and scintillation properties of (C6H5C2H4NH3)2Pb1−xZnxBr4 as a two-dimensional quantum-confined scintillator

Daichi Onoda, Masaki Akatsuka, Naoki Kawano, Daisuke Nakauchi, Takumi Kato, Noriaki Kawaguchi & Takayuki Yanagida

Journal of Materials Science: Materials in Electronics   31 ( 23 ) 1 - 7   2020.10  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation properties of Mn-doped methylammonium lead chloride crystals

Naoki Kawano, Masaki Akatsuka, Hiromi Kimura, Daisuke Nakauchi, Takumi Kato, Takayuki Yanagida

Journal of Materials Science: Materials in Electronics     2020.09  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Organic–inorganic perovskite materials with a bulk structure MAPbX3 (MA: methylamine, X: halogen) have attracted much attention in various applications such as solar cells, photodiodes, and radiation detectors. Herein, we synthesized (CH3NH3)Pb1-xMnxCl3 (or Mn-doped MAPbCl3) crystals by inverse temperature crystallization method to develop scintillator materials and evaluated their photoluminescence (PL) and scintillation properties systematically. The Mn-doped MAPbCl3 crystals showed a sharp emission peak at approximately 410–430 nm with short decay times on the order of nanoseconds and a broad peak at approximately 600 nm with a long decay time on the order of milliseconds in PL and scintillation. Furthermore, pulse height spectra of the Mn-doped MAPbCl3 crystals with a shaping time of 1 µs were measured, and the obtained scintillation light yields were estimated to be 66 (x = 1), 82 (x = 5), and 67 (x = 10) photons/5.5 MeV-α. Moreover, afterglow levels of the Mn-doped MAPbCl3 crystals were found to be 161 (x = 1), 264 (x = 5) and 170 (x = 10) ppm, which were comparable to a previously reported afterglow level of Tl-doped CsI.

DOI

Scintillation properties of organic-inorganic layered perovskite-type nanocrystals in glass

Naoki Kawano, Kenji Shinozaki, Daisuke Nakauchi, Hiromi Kimura, Takayuki Yanagida

Journal of Applied Physics   127   213103   2020.06  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Scintillation and dosimetric properties of Tb-doped CaF<inf>2</inf> translucent ceramics synthesized by the spark plasma sintering method

Naoki Kawano, Daisuke Nakauchi, Fumiya Nakamura, Takayuki Yanagida

Journal of Asian Ceramic Societies ( Journal of Asian Ceramic Societies )  8 ( 2 ) 484 - 491   2020.04  [Refereed]

Research paper (journal)   Domestic Co-author

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of The Korean Ceramic Society and The Ceramic Society of Japan. CaF2 translucent ceramics with different concentrations of Tb were synthesized by the spark plasma sintering (SPS) method, and their photoluminescence, scintillation and dosimetric properties were characterized. The Tb-doped samples exhibited scintillation with several sharp peaks across the range from 365–630 nm due to 4 f-4 f transitions of Tb3+ and with a broad peak at approximately 300 nm due to self-trapped excitons. Among the sample investigated, the scintillation intensity in the 365–630 nm range was highest for the 0.5% Tb-doped sample. As a dosimetric property, the Tb-doped samples exhibited thermally-stimulated luminescence (TSL) with a glow peak at approximately 90°C, and with a TSL response in a linear relationship to the X-ray dose over the dose range from 0.001 to 1 mGy. Optically stimulated luminescence (OSL) due to the 4 f-4 f transitions of Tb3+ was detected in the Tb-doped samples, moreover and the lowest detectable limit of OSL was at most 100 mGy.

DOI

Photoluminescence and scintillation properties of organic–inorganic perovskite-type compounds with bromophenethylamine

Atsushi Horimoto, Naoki Kawano, Daisuke Nakauchi, Hiromi Kimura, Masaki Akatsuka, Takayuki Yanagida

Sensors and Materials ( Sensors and Materials )  32 ( 4 ) 1395 - 1404   2020.04  [Refereed]

Research paper (journal)   Domestic Co-author

© MYU K.K. (n-BrC6H4C2H4NH3)2PbBr4 (n-BrPhe) (n = 2, 3, 4) single crystals were synthesized with the aim of enhancing the scintillation light yield of (C6H5C2H4NH3)2PbBr4 (Phe), and their photoluminescence (PL) and scintillation characteristics were evaluated. A sharp PL peak due to the exciton emissions from the inorganic layer was observed at 390–420 nm in the n-BrPhe samples. They had lifetimes of 4.7 ns (2-BrPhe), 2.1 ns (3-BrPhe), and 0.9 ns (4-BrPhe) owing to the exciton recombination in the inorganic layer under 340 nm excitation. Regarding scintillation, a sharp peak due to exciton emissions from the inorganic layer was detected at 410–440 nm under X-ray irradiation, and the decay time constants under X-ray irradiation were 2.3 ns (2-BrPhe), 2.0 ns (3-BrPhe), and 2.1 ns (4-BrPhe). Moreover, the scintillation light yields under gamma-ray irradiation from 241Am (59.5 keV) were found to be 3100 (2-BrPhe), 2200 (3-BrPhe), and 5900 photons/MeV (4-BrPhe), which were lower than that of Phe (18000 photons/MeV).

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