An Overview on the Research of Iron-Based High-Tc Superconductors Probed by X-ray Absorption Spectroscopy

The discovery in 2008 of a new family of high-Tc superconductor (HTSC), i.e., layered compounds based on iron, has spurred a tremendous interest in the community of condensed matter physics. This discovery has broken cuprate “monopoly” in the physics of HTSC materials. Until now, thousands of experimental and theoretical methods were devoted to investigate the superconducting properties of this new iron-based HTSCs. Synchrotron radiation-based X-ray absorption spectroscopy (XAS) made great contributions to the local lattice structure, the electronic structure, and even the superconductive mechanism of this iron-based materials. The aim of this review is a short introduction into the progress of research on new iron-based HTSCs probed by the unique technique—XAS, including the electron correlations, local lattice distortions, changes of valence upon doping or pressure, and even the isotope effect for this new iron-based family.