Phase Diagram and Weak-link Behavior in Nd-doped CaFe_2As_2
arXiv:1408.2310 · doi:10.1088/1367-2630/16/11/113024
Abstract
The transport properties, phase diagram, and dopant distribution are investigated in systematically Nd doped CaFe_2As_2 single crystals. Coexistence of two superconducting (SC) phases with different critical transition temperature (T_c) is observed. The low-T_c phase emerges as x >= 0.031, and the T_c value increases to its maximum value of about 20 K at x = 0.083, the maximum doping level in our study. As x >= 0.060, the high-T_c phase with a T_c value of about 40 K is observed. The structure transition (STr) from tetragonal to orthorhombic phase vanishes suddenly around x = 0.060, where a new STr from tetragonal to collapsed tetragonal phase begins to turn up. Compared to the low-T_c phase, the end point of SC transition of the high-T_c phase is more sensitive to the magnetic field, showing a characteristic of Josephson weak-link behavior. Possible scenarios about this system are discussed based on our observations. We also find that the non-uniform SC properties cannot be attributed to the heterogeneous Nd distribution on the micro scale, as revealed by the detailed energy dispersive X-ray spectroscopy (EDS) measurements.
arXiv comment12 pages, 5 figures
References in corpus (25)
- Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
- Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
- Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
- Determination of the phase diagram of the electron doped superconductor Ba(FeCo)As
- Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
- Superconductivity induced by Ni doping in BaFeAs
- Iron based high transition temperature superconductors
- Phase Diagram of Ba1-xKxFe2As2
- Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single crystal neutron and x-ray diffraction investigation
- Structural collapse and superconductivity in rare earth-doped CaFe2As2
- The Unusual Superconducting State at 49 K in Electron-Doped CaFe2As2 at Ambient
- Growth and characterization of A_{1-x}K_xFe_2As_2 (A = Ba, Sr) single crystals with x=0 - 0.4
- Superconductivity induced by doping Pd in SrFe2-xPdxAs2
- Superconductivity at 22.3 K in SrFe2-xIrxAs2
- Superconductivity and phase diagrams in 4d- and 5d-metal-doped iron arsenides SrFe_{2-x}M_xAs_2 (M = Rh, Ir, Pd)
- Tailoring the Superconductivity and Antiferromagnetic Order in SrFe2-xRhxAs2
- The B -> D* l nu form factor at zero recoil from three-flavor lattice QCD: A model independent determination of |V_cb|
- Local inhomogeneity and filamentary superconductivity in Pr-doped CaFeAs
- Synthesis and properties of La-doped CaFe2As2 single crystals with Tc = 42.7 K
- High field magneto-transport study of YBa2Cu3O7-Agx (x = 0.0 to 0.20)
- Nanoscale Surface Element Identification and Dopant Homogeneity in the High- Superconductor PrCaFeAs
- Transport properties and anisotropy in rare earth doped CaFe2As2 single crystals with Tc above 40 K
- Coexistence of two superconducting phases in Ca1-xLaxFe2As2
- Transport and magnetic properties of La-doped CaFeAs
- Separation of antiferromagnetism and high-temperature superconductivity in CaLaFeAs under pressure