Kurmaev E Z, McLeod J A, Skorikov N A, Finkelstein L D, Moewes A, Izyumov Yu A, Clarke S
Institute of Metal Physics, Russian Academy of Sciences-Ural Division, 620219 Yekaterinburg, Russia.
J Phys Condens Matter. 2009 Aug 26;21(34):345701. doi: 10.1088/0953-8984/21/34/345701. Epub 2009 Aug 6.
Resonant x-ray emission spectroscopy (XES) measurements at Fe L(2,3) edges and electronic structure calculations for LiFeAs and NaFeAs are presented. Experiment and theory show that in the vicinity of the Fermi energy, the density of states is dominated by contributions from Fe 3d states. The comparison of Fe L(2,3) XES with spectra of related FeAs compounds reveals similar trends in energy and the ratio of intensities of the L(2) and L(3) peaks (I(L(2))/I(L(3)) ratio). The I(L(2))/I(L(3)) ratio for all FeAs-based superconductors is found to be closer to that of metallic Fe than that of the strongly correlated FeO. We conclude that iron-based superconductors are weakly or, at most, moderately correlated systems.
本文展示了在LiFeAs和NaFeAs的铁L(2,3)边进行的共振X射线发射光谱（XES）测量以及电子结构计算。实验和理论表明，在费米能量附近，态密度主要由铁3d态的贡献主导。将铁L(2,3) XES与相关FeAs化合物的光谱进行比较，发现在能量以及L(2)和L(3)峰强度比（I(L(2))/I(L(3))比）方面存在相似趋势。发现所有基于FeAs的超导体的I(L(2))/I(L(3))比更接近金属铁的该比值，而非强关联的FeO的该比值。我们得出结论，铁基超导体是弱关联或至多是中等关联的体系。
