Electron energy loss spectroscopy of K0.7Fe1.7Se2 superconductor

Electronic structure and microstructure of ternary selenide superconductor K0.7Fe1.7Se2 have been investigated by transmission electron microscopy (TEM) and energy band structure calculations. Electron energy-loss spectroscopy (EELS) was performed to study K0.7Fe1.7Se2 experimentally. The individual inter-bands transitions were identified through the comparison between the energy loss peak positions with the partial density of states (PDOS) obtained by first principle calculation. The electron energy-loss near-edge fine structure (ELNES) were analyzed, the core-hole effect was found to play a key role in the simulation of ELNES. The results can present some insight into the interaction between superconductivity and electronic structure in this group of iron-related superconductor.