相关论文: High-T_c superconductivity induced by doping rare …
A new hight Tc Fe-based compound system, AFe2As2 with A = K, Cs, K/Sr and Cs/Sr has been found. Through electron-doping, Tc of the A = K and Cs compounds rises to ~37 K, and finally enter a spin-density-wave state (SDW) through further…
High-pressure superconductivity in a rare-earth doped Ca0.86Pr0.14Fe2As2 single crystalline sample has been studied up to 12 GPa and temperatures down to 11 K using designer diamond anvil cell under a quasi-hydrostatic pressure medium. The…
Measurements of the Hall effect, thermoelectric power, magnetic susceptibility and upper and lower critical fields were performed on single crystals of SrFe(2-x)Ni(x)As2, an FeAs-based superconducting system that exhibits a reduced…
We report the realization of superconductivity by an isovalent doping with phosphorus in LaFeAsO. X-ray diffraction shows that, with the partial substitution of P for As, the Fe$_2$As$_2$ layers are squeezed while the La$_2$O$_2$ layers are…
Polycrystalline Sr1-xNdxFeAsF samples were prepared at various Nd-doping levels using both a stoichiometric mixture of the starting materials and in slight excess amounts of FeAs. Susceptibility and resistivity of the samples were studied…
Single crystalline CaFe2As2 and (Ca1-xNax)Fe2As2 polycrystals (0 < x < 0.66) are synthesized and characterized using structural, magnetic, electronic transport, and heat capacity measurements. These measurements show that the…
In the electron doped compounds SrFe_(2-x)Co_xAs_2 superconductivity with T_c up to 20 K is observed for 0.2 < x < 0.4. Results of structure determination, magnetic susceptibility, electrical resistivity, and specific heat are reported. The…
The effects of simultaneous Sb doping on the superconductivity of 112-type Ca1-xRExFeAs2 (RE = La, Ce, Pr, and Nd) were studied through measurements of the magnetization and electrical resistivity. In Sb-free materials, the superconducting…
Here we report the synthesis and basic characterization of LaFe1-xCoxAsO for several values of x. The parent phase LaFeAsO orders antiferromagnetically (TN ~ 145 K). Replacing Fe with Co is expected to both electron dope the system and…
The magnetic and transport behaviors of cerium substituted iron oxy-arsenide superconductor with x = 0.1 to 0.4 fluoride (F) doping have been investigated in this report. Temperature dependent susceptibility and resistivity measurements…
We report the realization of superconductivity by 5d element Ir doping in LaFeAsO, a prototype parent compound of high-temperature iron based superconductors. X-ray diffraction patterns indicate that the material has formed the…
We report superconductivity in polycrystalline samples of the 1038-type compounds (Ca$_{1-x}$RE$_x$)$_{10}$(FeAs)$_{10}$(Pt$_3$As$_8$) up to T$_c$ = 35 K with RE = Y, La-Nd, Sm, Gd-Lu. The critical temperatures are independent of the…
The difference in thermal stability of F- and H- in 1111-type iron based superconductors, allows selective hydrogen elimination from non-superconductive CaFeAsF0.8H0.2 by thermal annealing. The analyzed chemical composition of the resulting…
By using solid state reaction method, we have synthesized the Pd-doped superconductor SrFe2-xPdxAs2. The systematic evolution of the lattice constants indicated that the Fe ions were successfully replaced by the Pd. By increasing the doping…
Following the discovery of superconductivity in an iron-based arsenide LaO1-xFxFeAs with a superconducting transition temperature (Tc) of 26 K[1], Tc was pushed up surprisingly to above 40 K by either applying pressure[2] or replacing La…
Pure phases of a new oxyarsenide superconductor of the nominal composition CeOFe0.9Co0.1As was successfully synthesized by solid state reaction in sealed silica ampoules at 1180 C. It crystallizes in the layered tetragonal ZrCuSiAs type…
The 1111-type iron arsenide hydride CaFe1-xCoxAsH was synthesized by high-pressure solid-state reaction, and its electronic structure and superconducting properties were investigated. Bulk superconductivity was observed at x = 0.07-0.26. A…
Superconductivity with zero resistance transition temperature (Tc) up to 8.4 K and 8.3 K can be obtained by doping cobalt and sodium in alfa-FeSe with the nominal composition of Fe0.92Co0.08Se and Na0.1FeSe, respectively. The electrical…
The recently discovered FeAs-based superconductors are a new, promising set of materials for both technological as well as basic research. They offer transition temperatures as high as 55 K as well as essentially isotropic and extremely…
We have successfully synthesized the fluo-arsenide SrFeAsF, a new parent phase with the ZrCuAsSi structure. The temperature dependence of resistivity and dc magnetization both reveal an anomaly at about T_{an} = 173 K, which may correspond…