Development of new high resolution X-ray detection material using valence change of rare earth ions

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05955
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Device related chemistry
• Research Institution: University of Miyazaki
• Principal Investigator: Koji Maeda 宮崎大学, 工学部, 教授 (50219268)
• Co-Investigator(Kenkyū-buntansha): 鈴木 秀俊 宮崎大学, 工学部, 准教授 (00387854) ; 境 健太郎 宮崎大学, 産学・地域連携センター, 准教授 (20336291)
• Project Period (FY): 2016-10-21 – 2019-03-31
• Keywords: ラジオフォトルミネッセンス / X線検出 / 希土類 / ホウリン酸塩 / 価数変化 / 蛍光体 / サマリウム / フォトルミネッセンス

Outline of Final Research Achievements

Focusing on the valence change phenomena of ions due to X-ray and radiation irradiation, we developed the material for high sensitivity X-ray detection by photoluminescence (PL) measurement using the difference luminescence wave length of both before and after irradiated ions. A borophosphate compounds added samarium (Sm) were prepared. By the X-ray irradiation, part of the Sm3+ ions valence changed to Sm2+. The relationship between the PL intensity of Sm2 + and the X-ray irradiation time was saturated in long-time irradiation. We found an empirical rule to express these relationships. In the case of Sr1-xBPO5 which was the strongest PL intensity in our samples, the saturation strength of PL intensity became stronger at x = 0.05. By reducing the amount of Sr, it is thought that the saturated PL intensity increased because the ratio of Sm ions occupying the Sr site increased.

Free Research Field

材料物性工学

Academic Significance and Societal Importance of the Research Achievements

X線や放射線を用いた検査は透過力が大きいことから医療や安全チェックなどの分野で最近急速に普及している。安価で高感度、高分解能の検出器が求められている。本研究は、イオンの価数変化を利用してX線などを検出（RPL現象）するという新しい手法を試み、まだあまり開発されていない価数変化材料を比較した。また、単に材料の比較だけでなく、材料のRPL現象を簡単に比較できる経験式を見出した点が学術的、社会的な意義が大きい。