【摘要】 氧化还原状态不仅是评估星球宜居性的关键因素，也是地球内部圈层和表层环境之间物质循环和耦合演化的重要驱动力。铁（Fe）是类地行星中含量最高的变价元素，因此Fe价态(通常用Fe³⁺/ΣFe或Fe³⁺/Fe²⁺表示)是反映体系氧逸度的关键参数。该文详细探讨了电子探针在测定地质样品Fe价态的理论基础及其应用方法，分析了与之相关的X射线的激发与吸收原理、自吸收效应以及配位场理论，阐释了Fe价态测定依赖的L线系谱线特征。在此基础上，对比了峰肩法与峰位漂移法的优缺点，展示了不同样品在电子轰击下的损伤情况。研究表明，电子探针直接测定Fe价态方法具有广泛的应用前景和明显的技术优势，但仍需根据不同样品的特点优化测试条件和流程，以提高测试的准确性和可靠性。该研究为进一步开发和推广Fe价态测定方法提供了理论支持和实践指导，具有重要的地球科学研究意义。更多还原

【Abstract】 The redox state is not only a key factor in assessing planetary habitability, but also a crucial variable connecting Earth’s interior spheres and surface environment via mass recycling and co-variation. Iron（Fe）, as the most abundant multivalent element in terrestrial planets, its oxidation state(expressed as Fe³⁺/ΣFe or Fe³⁺/Fe²⁺) being the most important parameter reflecting the oxygen fugacity of the system. This study thoroughly investigates the application and theoretical foundation of electron probe microanalysis（EPMA） in the determination of Fe oxidation states in geological samples. We comprehensively analyzed the principles of X-ray emission and absorption, self-absorption effect, and crystal field theory, providing a detailed elucidation of the spectral characteristics of Fe’s L-series lines. Accordingly, we compared the advantages and disadvantages of the peak shift method and the flank method, and examined the damage inflicted on samples under electron bombardment.The results demonstrate that EPMA holds extensive application potential and overwhelming advantages in the determination of Fe oxidation state, but the analytical protocol and condition must be optimized to enhance test accuracy and reliability according to the characteristics of different samples. This research offers theoretical support and practical guidance for further development and promotion of Fe valence determination methods, holding significant implications for earth science research.更多还原