Revisiting the electron-doped SmFeAsO: enhanced superconductivity up to 58.6 K by Th and F codoping

Abstract

In the iron-based high-Tc bulk superconductors, Tc above 50K was only observed in the electron-doped 1111-type compounds. Here we revisit the electron-doped SmFeAsO polycrystals to make a further investigation for the highest T-c in these materials. To introduce more electron carriers and less crystal lattice distortions, we study the Th and F codoping effects into the Sm-O layers with heavy electron doping. Dozens of Sm1-x Th-x FeAsO1-y F-y samples are synthesized through the solid state reaction method, and these samples are carefully characterized by the structural, resistive, and magnetic measurements. We find that the codoping of Th and F clearly enhances the superconducting T-c more than the Th or F single-doped samples, with the highest record T-c up to 58.6K when x= 0.2 and y= 0.225. Further element doping causes more impurities and lattice distortions in the samples with a weakened superconductivity.

References in corpus (10)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Superconductivity at 36 K in beta-Fe1.01Se with the compression of the interlayer separation under pressure
• The superconductivity at 18 K in LiFeAs system
• Superconductivity in Co-doped LaFeAsO
• Hydrogen in layered iron arsenide: indirect electron doping to induce superconductivity
• Th substituted SmFeAsO: structural details and superconductivity with Tc above 50 K
• Effect of pressure on the superconducting critical temperature of La[O_{0.89}F_{0.11}]FeAs and Ce[O_{0.88}F_{0.12}]FeAs
• Transition Temperature and Upper Critical Field in SmFeAsO1-xFx Synthesized at Low Heating Temperatures

Cited by in corpus (7)

• Copper doping effects on the superconducting properties of Sm-based oxypnictides
• High-pressure growth effects on the superconducting properties of Sm-based oxypnictide superconductors
• Effect of spark plasma sintering on the superconducting properties of Sm-based oxypnictide
• High-pressure growth effect on the properties of high-Tc iron-based superconductors: A short review
• Complete electronic phase diagram and enhanced superconductivity in fluorine-doped PrFeAsO1-xFx
• Synthesis and characterizations of arsenic doped FeSe bulks
• Fluorine-substitution-dependent phase diagram and superconducting properties of Sm-based oxypnictides synthesized by a high-pressure growth technique