Superconductivity in Fluorine-Arsenide Sr_{1-x}La_xFeAsF

Abstract

Since the discovery of superconductivity\cite{1} at 26 K in oxy-pnictide $LaFeAs{O}_{1-x}{F}_x$, enormous interests have been stimulated in the fields of condensed matter physics and material sciences. Among the five different structures in this broad type of superconductors\cite{2,3,4,5,6}, the ZrCuSiAs structure has received special attention since the $T_c$ has been quickly promoted to 55-56 K\cite{7,8,9,10,11} in fluorine doped oxy-pnictides REFeAsO (RE = rare earth elements). The superconductivity can also be induced by applying a high pressure to the undoped samples\cite{12,13}. The mechanism of superconductivity in the FeAs-based system remains unclear yet, but it turns out to be clear that any change to the structure or the building blocks will lead to a change of the superconducting transition temperatures. In this Letter, we report the fabrication of the new family of compounds, namely fluorine-arsenides DvFeAsF (Dv = divalent metals) with the ZrCuSiAs structure and with the new building block DvF instead of the REO (both the layers DvF and REO have the combined cation state of "+1"). The undoped parent phase has a Spin-Density-Wave like transition at about 173 K for SrFeAsF, 118 K for CaFeAsF and 153 K for EuFeAsF. By doping electrons into the system the resistivity anomaly associated with this SDW transition is suppressed and superconductivity appears at 32 K in the fluorine-arsenide Sr${}_{1-x}$La${}_x$FeAsF (x = 0.4). Our discovery here initiates a new method to obtain superconductors in the FeAs-based system.

11 pages, 4 figures, typos added, references added, and one figure added

References in corpus (15)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• The superconductivity at 18 K in LiFeAs system
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Superconductivity under high pressure in LaFeAsO
• Upper critical field, Hall effect and magnetoresistance in the iron-based layered superconductor LaFeAsO_{0.9}F_{0.1-δ}
• Hall effect and magnetoresistance in the normal state of the superconductor LaO${}_{0.9}$F${}_{0.1-x}$FeAs
• A Generic Two-band Model for Unconventional Superconductivity and Spin-Density-Wave Order in Electron and Hole Doped Iron-Based Superconductors
• SrFeAsF as a parent compound for iron pnictide superconductors
• Hall effect and magnetoresistance in single crystals of NdFeAsO${}_{1-x}$F${}_x$
• Cobalt-substitution-induced Superconductivity in a New Compound with ZrCuSiAs-type Structure, SrFeAsF

Cited by in corpus (13)

• High-T_c superconductivity induced by doping rare earth elements into CaFeAsF
• Evolution of bulk superconductivity in SrFe2As2 with Ni substitution
• Magnetic order in CaFe1-xCoxAsF (x = 0, 0.06, 0.12) superconductor compounds
• Neutron spin resonance in a quasi-two-dimensional iron-based superconductor
• Superconducting and thermoelectric properties of new layered Superconductor Bi4O4S3
• Anion height dependence of Tc and density of states in iron based superconductors
• Spin-phonon coupling and pressure effect in the superconductor LiFeAs : Lattice dynamics from first-principles calculations
• Multigap superconductivity in ThAsFeN investigated using muSR measurements
• Two-dimensional magnetism in the pnictide superconductor parent material SrFeAsF probed by muon-spin relaxation
• Striped antiferromagnetism and electronic structures of SrFeAsF and their implications
• Upper critical field, critical current density and thermally activated flux flow in CaFFe0.9Co0.1As superconductor
• Effect of antifluorite layer on the magnetic order in Eu-based 1111 compounds, EuTAsF (T = Zn, Mn, and Fe)
• Band structure of tetragonal and orthorhombic fluorine-arsenide SrFeAsF as a parent phases for a new group of oxygen-free FeAs superconductors