Local lattice and electronic structures in the Fe-As layer of SmFeAsO 1-x Fx superconductors were studied by x-ray absorption spectroscopy, the FeK -edge and the AsK -edge extended x-ray absorption fine-structure, and x-ray absorption near-edge-structure experiments, respectively. Temperature-dependent local lattice distortions were observed in the Fe-As bond mean-square relative displacement of the superconducting samples. A strong coupling of the carrier-induced local lattice distortion (polaron) to the superconducting transition temperature in the oxypnictide superconductors is indicated. The near-edge spectra showed systematic temperature-dependent energy shifts, which indicate an intralayer electron redistribution from Fed states to Asp states due to orbital-selective band filling at low temperatures.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2010 Mar 17|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics