论文标题
配体状态在基于母体Fe的超导体CAFE2AS2的电子特性中的异常作用
Unusual role of ligand states in the electronic properties of a parent Fe-based superconductor, CaFe2As2
论文作者
论文摘要
我们使用高分辨率硬X射线光发射光谱（HAXPE）在不同样品温度下研究了配体状态在CAFE2AS2的电子性质中的作用。实验结果表明，Ca的结合能与Ca原子的2+电荷状态和其他组成元素（Fe），Fe和具有接近元素系统中的电子构型的结合能。随着发射角和/或样品温度变化的变化，在AS 3P核心水平光谱中未观察到差异。这是令人惊讶的，因为切割样品表面的Ca原子重新组织自身形成线性结构，这有望影响CA-AS杂交，从而导致表面和散装电子结构的显着差异。此外，CAFE2AS2在170 K处进行结构和磁相变，强大的Fe-AS杂交为电子动力学提供了途径。显然，需要进一步的研究来解决这些令人困惑的观察结果。
We investigate the role of ligand states in the electronic properties of CaFe2As2 using high-resolution hard x-ray photoemission spectroscopy (HAXPES) at different sample temperatures. Experimental results indicate that the binding energy of Ca is close to that for 2+ charge state of Ca atoms and the other constituent elements, Fe and As possess electronic configuration close to that in elemental systems. No difference is observed in the As 3p core level spectra with the change of emission angle and/or the change in sample temperature. This is surprising as the Ca atoms at the cleaved sample surface reorganizes itself to form linear structures which is expected to influence Ca-As hybridization leading to significant difference in surface and bulk electronic structures. Moreover, CaFe2As2 undergoes structural and magnetic phase transition at 170 K, and strong Fe-As hybridization provides pathways for electron dynamics. Clearly, further studies are required to resolve these puzzling observations.
