High-T_c superconductivity induced by doping rare earth elements into CaFeAsF

Abstract

We have successfully synthesized the fluoride-arsenide compounds Ca${}_{1-x}$RE${}_x$FeAsF (RE=Nd, Pr; x=0, 0.6). The x-ray powder diffraction confirmed that the main phases of our samples are Ca${}_{1-x}$RE${}_x$FeAsF with the ZrCuSiAs structure. By measuring resistivity, superconductivity was observed at 57.4 K in Nd-doped and 52.8 K in Pr-doped samples with x=0.6. Bulk superconductivity was also proved by the DC magnetization measurements in both samples. Hall effect measurements revealed hole-like charge carriers in the parent compound CaFeAsF with a clear resistivity anomaly below 118 K, while the Hall coefficient $R_H$ in the normal state is negative for the superconducting samples Ca${}_{0.4}$Nd${}_{0.6}$FeAsF and Ca${}_{0.4}$Pr${}_{0.6}$FeAsF. This indicates that the rare earth element doping introduces electrons into CaFeAsF which induces the high temperature superconductivity.

4 pages, 4 figures

References in corpus (12)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
• Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAs
• Structure and superconductivity of LiFeAs
• Synthesis, crystal structure and spin-density-wave anomaly of the iron arsenide-fluoride SrFeAsF
• SrFeAsF as a parent compound for iron pnictide superconductors
• Cobalt-substitution-induced Superconductivity in a New Compound with ZrCuSiAs-type Structure, SrFeAsF
• Superconductivity in Fluorine-Arsenide Sr_{1-x}La_xFeAsF
• Effect of 3d Transition Metal Doping on the Superconductivity in Quaternary Fluoroarsenide CaFeAsF

Cited by in corpus (3)

• Superconductivity at 17 K in (Fe2P2)(Sr4Sc2O6): a new superconducting layered pnictide oxide with a thick perovskite oxide layer
• Evolution of bulk superconductivity in SrFe2As2 with Ni substitution
• Microscopic origin of pressure-induced phase transitions in iron-pnictide $AF{e}_{2}A{s}_2$ superconductors: an {ab initio} molecular-dynamics study