Development of luminescence imaging system using Focused Ion Beam microscope and three-dimensional observation of microtextures in minerals

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H01298
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: The University of Tokyo (2019-2021); Tohoku University (2018)
• Principal Investigator: Kayama Masahiro 東京大学, 大学院総合文化研究科, 助教 (30634068)
• Co-Investigator(Kenkyū-buntansha): 三宅 亮 京都大学, 理学研究科, 准教授 (10324609)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: ルミネッセンス / 鉱物 / 集束イオンビーム / 微細組織 / 石英 / 長石 / インパクタイト

Outline of Final Research Achievements

High-resolution luminescence imaging system, Focused Ion Beam microscope combined with luminescence detector, was newly developed to visualize　microtextures and structures in constituent minerals. This system enables us to find planar deformation features (PDFs), microstructure formed by shock metamorphism, in quartz more easily than the conventional methods. Existence of PDFs in minerals place constraints on shock pressure that meteorite and impactite have experienced, estimating the scale of impact events on impact craters. Rhombus-shaped microtextures was observed in high-temperature metamorphic quartz in felsite inclusion by the luminescence imaging system and it reflects the external shape of high-temperature quartz. This suggests that the felsite inclusion formed by high-temperature metamorphism with rapid cooling. Our luminescence imaging system provides various new application to the evaluation of thermal and shock-metamorphic histories in planetary science and geosciences.

Free Research Field

鉱物学、隕石学、惑星科学、地球科学

Academic Significance and Societal Importance of the Research Achievements

このイメージングシステムはFIBを基盤としているため、従来の手法では困難であった1マイクロメートル以下の空間分解能での観測を実現する。サブミクロンオーダーでの組織・構造を非破壊かつ容易に観察が可能であり、いくつかの新奇的な地球・惑星学的応用を達成した。さらにルミネッセンスは物理学において半導体の評価や発光デバイスの開発などに必要な常套手段であり、本システムの流用から学際的なさらなる成果が期待される。