Development of multi-component garnet scintillators for Medical applications

• Project/Area Number: 17F17379
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 外国
• Research Field: Inorganic materials/Physical properties
• Research Institution: Tohoku University
• Principal Investigator: 吉川 彰 東北大学, 金属材料研究所, 教授 (50292264)
• Co-Investigator(Kenkyū-buntansha): BARTOSIEWICZ KAROL 東北大学, 金属材料研究所, 外国人特別研究員
• Project Period (FY): 2017-11-10 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥2,300,000 (Direct Cost: ¥2,300,000); Fiscal Year 2019: ¥500,000 (Direct Cost: ¥500,000); Fiscal Year 2018: ¥1,100,000 (Direct Cost: ¥1,100,000); Fiscal Year 2017: ¥700,000 (Direct Cost: ¥700,000)
• Keywords: シンチレータ / ガーネット / トラップ / 蛍光寿命 / 共添加効果 / scintillaotr / Garnet / Optical materials / single crystal / ガーネット型結晶

Outline of Annual Research Achievements

放射線を光検出器で検出できるようにする光学材料であるシンチレータの中で、ガーネット型と呼ばれる酸化物単結晶は近年その研究が盛んである。このガーネット型結晶のグループの中で、効率よくガンマ線を検出できる結晶材料・組成の最適化を本研究では行った。
ガドリニウムやアルミニウムといった今まで研究してきたガーネット型結晶の主成分と、発光させるためのセリウム元素の調合比の最適化が今までメインであった。最近、これまでは利用されてこなかった、カルシウムといったアルカリ土類金属元素を、非常にわずかな量（ガドリニウムの1万分の1以下）添加することで、特性が変化することが分かってきた（微量元素共添加効果）。そこで、本研究では、この微量元素共添加効果のメカニズムを解明する一環として、アルカリ金属であるリチウムなどでも同様の効果があるかを検証した。
結晶は、マイクロ引き下げ法と呼ばれる方法で育成し、研磨加工ののちに、発光量や蛍光寿命とったシンチレータの特性について調査した。
その結果、リチウム添加のガーネットでは、リチウムの添加量を多くすることで、蛍光寿命の高速化を実現することができたが、一方で発光量の低下も生じさせたことから、消光現象がおきているのみということが分かってきた。シンチレータの発行のプロセスの中で、放射線が入射してから発光までの過程で、発光を阻害するような「トラップ」がどの位あるかを、リチウム添加量ごとに調べたところ、やはりリチウムの添加量ととともに、トラップが生成されてるということが分かった。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Kazimierz Wielki University in Bydgoszcz(ポーランド)
• [Int'l Joint Research] Czech Academy of Sciences(チェコ)
• [Int'l Joint Research] The Czech Academy of Sciences/Kazimierz Wielki University in Bydgoszcz(チェコ)
• [Journal Article] Lead-free piezoelectric crystals grown by the micro-pulling down technique in the BaTiO3?CaTiO3?BaZrO3 system (2019)
  • Author(s): Veber Philippe、Bartosiewicz Karol、Debray Jerome、Alombert-Goget Guillaume、Benamara Omar、Motto-Ros Vincent、Pham Thi Mai、Borta-Boyon Ana、Cabane Hugues、Lebbou Kheirreddine、Levassort Franck、Kamada Kei、Yoshikawa Akira、Maglione Mario
  • Journal Title: CrystEngComm Volume: 21 Issue: 25 Pages: 3844-3853
  • DOI: 10.1039/c9ce00405j
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Relationship Between Li/Ce Concentration and the Luminescence Properties of Codoped Gd3(Ga, Al)5O12:Ce (2019)
  • Author(s): Yoshino Masao、Bartosiewicz Karol、Horiai Takahiko、Kamada Kei、Yamaji Akihiro、Shoji Yasuhiro、Yokota Yuui、Kurosawa Shunsuke、Ohashi Yuji、Sato Hiroki、Toyoda Satoshi、Kucerkova Romana、Jary Vitezslav、Nikl Martin、Yoshikawa Akira
  • Journal Title: physica status solidi (b) Volume: - Issue: 8 Pages: 1900504-1900504
  • DOI: 10.1002/pssb.201900504
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Ga for Al substitution effects on the garnet phase stability and luminescence properties of Gd3GaxAl5-xO12:Ce single crystals (2019)
  • Author(s): Bartosiewicz K.、Babin V.、Kamada K.、Yoshikawa A.、Kurosawa S.、Beitlerova A.、Kucerkova R.、Nikl M.、Zorenko Yu
  • Journal Title: Journal of Luminescence Volume: 216 Pages: 116724-116724
  • DOI: 10.1016/j.jlumin.2019.116724
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effects of Gd/Lu ratio on the luminescence properties and garnet phase stability of Ce3+ activated GdxLu3-xAl5O12 single crystals (2018)
  • Author(s): K. Bartosiewicz, V. Babin, K. Kamada, A. Yoshikawa, A. Beitlerova, M. Nik
  • Journal Title: Optical Materials Volume: 80 Pages: 98-105
  • DOI: 10.1016/j.optmat.2018.04.023
  • Peer Reviewed / Int'l Joint Research
• [Presentation] The Al for Sc substitution effects on the scintillation properties of Lu3Ga2.5Al2.5-xScxO12:Pr single crystals (2019)
  • Author(s): Karol Bartosiewicz, Akira Yoshikawa, Shunsuke Kurosawa, Akihiro Yamaji, Yuryi Zorenko, Martin Nikl
  • Organizer: 15th International conference on Scintillating Materials and their Applications (SCINT2019)
  • Int'l Joint Research
• [Presentation] Advanced three layered composite scintillators based on the epitaxial structures of garnet compounds (2019)
  • Author(s): S. Witkiewicz-Lukaszek, V. Gorbenko, T. Zorenko, Y. Zorenko, J.A. Mares, R. Kucerkova, M. Nikl, O. Sidletskiy, K. Bartosiewicz, K. Kamada, S. Kurosawa, A. Yoshikawa
  • Organizer: 15th International conference on Scintillating Materials and their Applications (SCINT2019)
  • Int'l Joint Research
• [Presentation] Cerium and Lithium concentration effect on scintillation properties and temperature dependence of Gd3(Ga, Al)5O12 scintillator (2019)
  • Author(s): Masao Yoshino, Karol Bartosiewicz, Kei Kamada, Yasuhiro Shoji, Yuui Yokota, Shunsuke Kurosawa, Yuji Ohashi, Hiroki Sato, Akihiro Yamaji, Martin Pokorny, Alena Beitlerova, Romana Kucerkova, Martin Nikl, And Akira Yoshikawa
  • Organizer: 8th International Symposium on Optical Materials (IS-OM 8)
  • Int'l Joint Research
• [Presentation] Effects of La doped on the crystal growth and intrinsic luminesce properties of Lu3Al5O12 single crystal (2019)
  • Author(s): Karol Bartosiewicz, Shunsuke Kurosawa, Akira Yamaji, Martin Nikl, Akira Yoshikawa, Yuriy Zorenko
  • Organizer: 19th International Conference on Crystal Growth and Epitaxy (ICCGE-29)
  • Int'l Joint Research
• [Presentation] The Lu for La substitution effects on the single crystal growth and luminescence properties in Lu3-xLaxGa3Al2O12:Ce3+ scintillators (2019)
  • Author(s): K. Bartosiewicz, A. Yoshikawa, S. Kurosawa, A. Yamaji, M. Nikl, Yu. Zorenko
  • Organizer: The 66th Japan Society of Applied Physics, Spring Meeting, Tokyo, 2019
• [Presentation] Codoping Effects on Luminescence and Scintillation Properties of Multicomponent Garnets (2018)
  • Author(s): K. Bartosiewicz, V. Babin, M. Nikl, D. Panek, P. Bruza, A. Yoshikawa, K. Kamada, W. Chewpraditkul, N. Pattanaboonmee, S. Omelkov
  • Organizer: The 135th IMR Lecture Meeting, Tokoku University
• [Presentation] Effect of Mg2+ codoping on cathodoluminescence properties of Ce3+ activated GGAG single crystals (2018)
  • Author(s): K. Bartosiewicz, S. Omelkov, A. Beitlerova, P. Bohacek, M. Nikl, A. Yoshikawa
  • Organizer: The 65th Japan Society of Applied Physics, Spring Meeting, Tokyo, 2018
  • Int'l Joint Research
• [Presentation] Effect of Ce and Mg concentration ratio on the properties of Gd3Al2Ga3O12 single crystal scintillators (2018)
  • Author(s): K. Bartosiewicz, A. Yoshikawa, S. Kurosawa, A. Yamaji, M. Nikl, Yu. Zorenko
  • Organizer: The 2018 Europhysical Conference on Defects in Insulating Materials (EURODIM 2018), Poland
• [Presentation] The Ce and Li concentration ratio influence on the scintillation and luminescence features in Gd3Ga3Al2O12 single crystals (2018)
  • Author(s): K. Bartosiewicz, A. Yoshikawa, S. Kurosawa, A. Yamaji, M. Nikl, Yu. Zorenko
  • Organizer: Luminescent Detectors and Transformers of Ionizing Radiation (LUMDERT 2018), Czech Republic
• [Presentation] The effect of Li and Mg codoping strategy on the properties of Gd3Ga3Al2O12 single Crystal scintillators (2018)
  • Author(s): K. Bartosiewicz, A. Yoshikawa, S. Kurosawa, A. Yamaji, M. Nikl, Yu. Zorenko
  • Organizer: The 79th Japan Society of Applied Physics, Autumn Meeting, Nagoya, 2018
• [Presentation] Effect of Mg²⁺ codoping on cathodoluminescence properties of Ce³⁺ activated GGAG single crystals (2018)
  • Author(s): Karol Bartosiewicz, Sergey Omelkov, Alena Beitlerova, Pavel Bohacek, Martin Nikl, Akira Yoshikawa
  • Organizer: 第65回応用物理学会春季学術講演会