Low-temperature lattice anomaly in LaFeAsO0.93F0.07 probed by x-ray absorption spectroscopy: Evidence for strong electron-lattice interaction

Abstract

The local lattice structure in newly discovered LaFeAsO1-xFx superconductors is studied by extended x-ray absorption fine structure measurements. An anomalous upturn of the mean-square relative displacement of the Fe-As bond is detected below ~70 K as electron carriers are introduced,reflecting the occurrence of Fe-As bond local lattice fluctuation. Similar to that in cuprates, this lattice fluctuation exhibits an abrupt depression at the onset superconducting transition temperature. The results indicate that strong electron-lattice interaction is involved in the superconducting transition in oxypcnictide superconductors, putting a strict limitation on possible theoretical models.

15 pages, 6 figures

References in corpus (5)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
• Crystallographic Phase Transition and High-Tc Superconductivity in LaFeAsO:F
• Superconducting Gap and Pseudogap in Iron-Based Layered Superconductor La(O${}_{1-x}$F${}_x$)FeAs

Cited by in corpus (7)

• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• Local structure of REFeAsO (RE=La, Pr, Nd, Sm) oxypnictides studied by Fe K-edge EXAFS
• RE L${}_3$ X-ray absorption study of REO${}_{1-x}$F${}_x$FeAs (RE=La, Pr, Nd, Sm) oxypnictides
• Temperature dependent local atomic displacements in Ru substituted SmFe_{1-x}Ru_{x}AsO_{0.85}F_{0.15} superconductors
• Temperature dependent local structure of NdFeAsO1-xFx system using arsenic K-edge extended x-ray absorption fine structure
• Importance of structural distortions in enhancement of transition temperature in FeSe${}_{1-x}$Te${}_x$ superconductors
• Temperature dependent As K-edge EXAFS studies of LaFe1-xCoxAsO (x = 0.0 and 0.11) single crystals