Stephens Jack, Rijal Ramesh, Sier Daniel, Tran Nicholas T T, Dean Jonathan W, Di Pasquale Paul, Kirk Tony, Dao Minh, Tran Chanh Q, Hayama Shusaku, Diaz-Moreno Sofia, Chantler Christopher T
School of Physics, University of Melbourne, Melbourne, Victoria, Australia.
Department of Chemistry and Physics, La Trobe University, Melbourne, Victoria, Australia.
IUCrJ. 2025 Sep 1;12(Pt 5):548-562. doi: 10.1107/S2052252525005573.
The discovery of the novel n = 2 satellite transition in the Kβ emission spectrum of manganese and its evolution with incident photon energy are presented. Using the XR-HERFD (extended-range high-energy-resolution fluorescence detection) technique, we conclusively demonstrate the existence of this phenomenon with a statistical significance corresponding to 652 σ across the measured spectrum, far above the discovery threshold of 3-6 σ. We apply principal component analysis (PCA) to the XR-HERFD data to extract advanced structural insights. The evolution of this novel spectral feature and physical process are quantified by incorporating regression, revealing the increase in intensity over a wide range of incident photon energies. We validate these findings through independent test data. These results directly challenge the conventional treatment of the many-body reduction factor S as a constant independent of incident photon energy in the standard XAFS (X-ray absorption fine structure) equation. Thereby, these results present compelling evidence that S should be modelled as a varying function of incident photon energy, marking the first observation of this behaviour in Kβ spectra. This facilitates a greater quantitative understanding of HERFD spectra and a comprehensive representation of many-body effects in condensed matter systems.
本文介绍了在锰的Kβ发射光谱中发现的新型n = 2卫星跃迁及其随入射光子能量的演化。使用XR-HERFD（扩展范围高能分辨率荧光检测）技术，我们在整个测量光谱中以相当于652σ的统计显著性确凿地证明了这一现象的存在，远高于3-6σ的发现阈值。我们对XR-HERFD数据应用主成分分析（PCA）以提取深入的结构见解。通过纳入回归对这一新型光谱特征和物理过程的演化进行量化，揭示了在广泛的入射光子能量范围内强度的增加。我们通过独立测试数据验证了这些发现。这些结果直接挑战了在标准XAFS（X射线吸收精细结构）方程中多体约化因子S作为与入射光子能量无关的常数的传统处理方式。因此，这些结果提供了令人信服的证据，表明S应被建模为入射光子能量的变化函数，这是在Kβ光谱中首次观察到这种行为。这有助于对HERFD光谱有更深入的定量理解，并全面描述凝聚态物质系统中的多体效应。
