近日，日本冈山大学Takahiro Hiraki团队研究了氟化钙中钍-229的激光穆斯堡尔谱学。这一研究成果于2026年8月20日发表在《科学》期刊上。

穆斯堡尔光谱学广泛应用于化学、地质学和固体物理学中，用以探测材料中原子核的局域物理和化学环境。

研究组将该技术扩展至光学波段，利用真空紫外激光探测掺入氟化钙（CaF2）晶体中钍-229（229Th）的低能核跃迁。结果发现了钍离子的四种不同掺杂位点，确定了由与主体晶体相互作用所产生的特征电场梯度，并识别出两种主要构型的微观结构。通过位点选择性激光激发，研究组得以分析所有位点的同质异能态寿命及激光诱导淬灭效应。该技术为核环境探测提供了有力手段，为未来固态核钟的设计奠定了关键数据基础。

附：英文原文

Title: Laser Mssbauer spectroscopy of 229Th in CaF2

Author: Takahiro Hiraki, Takahiko Masuda, Sayuri Takatori, Fabian Schaden, Michael Bartokos, Kjeld Beeks, Yuta Fukunaga, Andreas Grüneis, Ming Guan, Georgy Kazakov, Thomas LaGrange, Adrian Leitner, Ira Morawetz, Ryoichiro Ogake, Koichi Okai, Martin Pimon, Martin Pressler, Thomas Riebner, Noboru Sasao, Felix Schneider, Thorsten Schumm, Kotaro Shimizu, Luca Toscani de Col, Tomas Sikorsky, Akihiro Yoshimi, Koji Yoshimura

Issue&Volume: 2026-08-20

Abstract: Mssbauer spectroscopy is widely used in chemistry, geology, and solid-state physics to probe the local physical and chemical environment of nuclei in materials. Here, we extended this technique into the optical range using a vacuum ultraviolet laser to probe the low-energy nuclear transitions of thorium-229 (229Th) doped in calcium fluoride (CaF2) crystals. We discovered four distinct doping sites for the thorium ions, determined the characteristic electric field gradients emerging from the interaction with the host crystal, and identified the microscopic structure of the two dominant configurations. Site-selective laser excitation enabled the study of the isomeric state lifetime and laser-induced quenching for all sites. This technique provides a powerful probe of the nuclear environment, yielding foundational data for designing future solid-state nuclear clocks.

DOI: aea7978

Source: https://www.science.org/doi/10.1126/science.aea7978