Related papers: Understanding doping, vacancy, lattice stability a…
The nature of spin-density wave and its relation with superconductivity are crucial issues in the newly discovered Fe-based high temperature superconductors. Particularly it is unclear whether the superconducting phase and spin density wave…
The relationship between unconventional superconductivity, antiferromagnetism and nematic order in iron-based superconductors (FeSCs) is still highly debated. In many FeSCs superconductivity is in proximity of a nematically and magnetically…
Superconductivity originates from pairing of electrons. Pairing channel on Fermi surface and pairing glue are thus two pivotal issues for understanding a superconductor. Recently, high-temperature superconductivity over 40 K was found in…
In this paper we report the synthesis of iron-based superconductors CaFe2-xRhxAs2 using one-step solid state reaction method, which crystallizes in the ThCr2Si2-type structure with a space group I4/mmm. The systematic evolution of the…
Chemical doping has recently become a very important strategy to induce superconductivity especially in complex compounds. Distinguished examples include Ba-doped La$_2$CuO$_4$ (the first high temperature superconductor), K-doped BaBiO$_3$,…
The high-Tc alkali doped iron selenide superconductors KxFe{2-y}Se2 have been recently shown to be intrinsically phase separated into Fe vacancy ordered block antiferromagnetic regions and superconducting regions at low temperatures. In…
We address the ferromagnetic tendencies detrimental for superconductivity that are related to the substitution of the pnictogen As atom with Ge or Si, together with additional substitutions in the spacer layers in 122 and 1111 Fe-based…
Iron-based superconductors (FBS) comprise several families of compounds having the same atomic building blocks for superconductivity, but large discrepancies among their physical properties. A longstanding goal in the field has been to…
We carried out a comparative study of the in-plane resistivity and optical spectrum of doped BaFe2As2 and investigated the doping evolution of the charge dynamics. For BaFe2As2, charge dynamics is incoherent at high temperatures. Electron…
Intercalation of two-dimensional (2D) iron chalcogenides with molecular species requires disentangling electronic and structural contributions to understand the puzzling limit to superconducting transition temperature ($T_c$) at the…
Very recently (November, 2010, PRB, 82, 180520R) the first 122-like ternary superconductor KxFe2Se2 with enhanced TC ~ 31K has been discovered. This finding has stimulated much activity in search of related materials and triggered the…
We present a brief review of the present day situation with studies of high-temperature superconductivity in iron pnictides and chalcogenides. Recent discovery of superconductivity with T_c > 30 K in A_xFe_{2-x/2}Se_2 (A=K,Cs,Tl,...)…
The recently discovered LaFe2As2 superconducting compound, member of the 122 family of iron pnictide superconductors, becomes superconducting below Tc=13K, yet its nominal doping apparently places it in the extreme overdoped limit, where…
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…
A1-xFe2-ySe2 (A = K, Cs, Rb, Tl) are recently discovered iron-based superconductors with critical temperatures (Tc) ranging up to 32 K. Their parent phases have unique properties when compared with other iron-based superconductors; e.g.,…
Fe-based superconductors exhibit a diverse interplay between charge, orbital, and magnetic ordering1-4. Variations in atomic geometry affect electron hopping between Fe atoms5,6 and the Fermi surface topology, influencing magnetic…
Using one-step solid state reaction method, we have successfully synthesized the superconductor SrFe1-xRuxAs. X-ray diffraction indicates that the material has formed the ThCr2Si2-type structure with a space group I4/mmm. The systematic…
The superconducting state of iron pnictides and chalcogenides exists at the border of antiferromagnetic order. Consequently, these materials could provide clues about the relationship between magnetism and unconventional superconductivity.…
Whether the newly discovered KxFe2-ySe2 systems are doped Mott or band insulators is key to how superconductivity emerges at lower temperature. With extant theoretical studies supporting conflicting scenarios, a more realistic approach is…
In the layered iron-based superconductor YFe2Ge2, a high Sommerfeld ratio of ~100 mJ/molK^2 and a T^(3/2) temperature dependence of the electrical resistivity at low temperature T indicate strong electronic correlations and point towards an…