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

Electronic structure and microstructure of ternary selenide superconductor K 0.7 Fe 1.7 Se 2 have been investigated by transmission electron microscopy (TEM) and energy band structure calculations. Electron energy-loss spectroscopy (EELS) was performed to study K 0.7 Fe 1.7 Se 2 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.