Study of the atomic-scale in-situ process of mechanoluminscence

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K20912
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 14:Plasma science and related fields
• Research Institution: Saga University
• Principal Investigator: Zheng Xu-Guang 佐賀大学, 理工学部, 教授 (40236063)
• Co-Investigator(Kenkyū-buntansha): 山内 一宏 佐賀大学, 理工学部, 准教授 (60444395)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 応力発光 / ミュオンスピン緩和 / 発光過程の動的解析 / 強磁性

Outline of Final Research Achievements

Mechanoluminescence (ML) is luminescence induced by mechanical stimuli.It is a promising technology, but its mechanism remains largely unknown. We believed that the key for the ML mechanism in a representative material SAO lies in the dynamic interplay between the rare-earth luminescent centers and the crystal defects during mechanical excitation. Meanwhile, the movement of the dislocations may influence the trapping of muons implanted. We thus conceived the idea of studying the dynamic interplay of luminescent centers and crystal defects at an atomic scale using muSR. We have found strong correlation of the mSR spectra to the ML property, which opened the route for future studies. We have successfully grown transparent crystals of SAO, which is optimum for future experiments. Besides, we also discovered unexpected ferromagnetism in the ML materials.

Free Research Field

物性物理学

Academic Significance and Societal Importance of the Research Achievements

応力発光物質は、低い力学刺激でも発光することから、バイオイメージング、応力分布可視化・破壊予知・亀裂診断など、人工骨から橋梁やタンクなどの巨大建造物の健全性診断まで適用でき、中高期に入った社会インフラ等の保守点検および安全・安心な社会を支える要素技術として強く期待されている。
しかし、今までの研究は応力発光の性能向上と材料開発を中心に行わってきており、これら画期的な応力発光性に潜むメカニズムは、実質上、現象的な考察しか行われていない。メカニズムの解明は、本格的な新学術領域展開のカギとなる。