Related papers: The local atomic structure of superconducting Fe-S…
We report the evolution of superconductivity and the phase diagram of the KxFe2-ySe2-zTez (z=0-0.6) crystals grown by a simple one-step synthesis. No structural transition is observed in any crystals, while lattice parameters exhibit a…
Pnictogens and chalcogens are both viable anions for promoting Fe-based superconductivity and intense research activity in the related families has established systematic correlation between the Fe-anion height and the superconducting…
We report density functional studies of the Fe$_{1-x}$Cu$_x$Se alloy done using supercell and coherent potential approximation methods. Magnetic behavior was investigated using the disordered local moment approach. We find that Cu occurs in…
The symmetry and structure of the superconducting gap in the Fe-based superconductor are the central issue for understanding these novel materials. So far the experimental data and theoretical models have been highly controversial. Some…
The symmetry and structure of the superconducting gap in the Fe-based superconductors are the central issue for understanding these novel materials. So far the experimental data and theoretical models have been highly controversial. Some…
We studied the correlation among structure and transport properties and superconductivity in the different $A_x$Fe$_2$Se$_2$ single crystals ($A$ = K, Rb, and Cs). Two sets of (00$l$) reflections are observed in the X-ray single crystal…
We observed in superconducting (Tl,Rb)2Fe4Se5 spin-wave branches that span an energy range from 6.5 to 209 meV. Spin dynamics are successfully described by a Heisenberg localized spin model whose dominant in-plane interactions include only…
Single crystal synchrotron X-ray diffraction as a function of temperature and pressure has revealed a complex biphase mixture in superconducting FeSe. Based on our experimental results we construct a phase diagram where structural behavior…
In this letter, we report that the superconductivity transition temperature in beta-Fe1.01Se increases from 8.5 to 36.7 K under applied pressure of 8.9 GPa. It then decreases at higher pressure. A dramatic change in volume is observed at…
We present a systematic angle-resolved photoemission spectroscopy study of the substitution-dependence of the electronic structure of Rb$_{0.8}$Fe$_{2}$(Se$_{1-z}$S$_z$)$_2$ (z = 0, 0.5, 1), where superconductivity is continuously…
We present measurements of resistivity and thermopower of Fe1+xTe1-ySey single crystalline samples with y=0, 0.1, 0.2, 0.3 and 0.45 in zero field and in a magnetic field B=8T. We propose a qualitative analysis of the temperature behavior of…
We have performed $^{125}$Te NMR on a single crystal of the novel layered superconductor Fe$_{1.04}$Te$_{0.67}$Se$_{0.33}$ for the first time. The spin parts of the Knight shifts for both $H // a$, $H // c$ are suppressed in the…
The spin-fluctuation effect in the Se-substituted system Fe$_{1+\delta}$Te$_{1-x}$Se$_x$ ($x$ = 0, 0.05, 0.12, 0.20, 0.28, 0.33, 0.45, 0.48 and 1.00; $0<\delta < 0.12$) has been studied by the measurements of the X-ray diffraction, the…
In this work we present a systematic experimental and theoretical study of the structural, transport and superconducting properties of Sm(Fe1-xRux)As(O0.85F0.15) polycrystalline samples as a function of Ru content (x) ranging from 0 to 1.…
Bulk magnetization, transport and neutron scattering measurements were performed to investigate the electronic and magnetic properties of a polycrystalline sample of the newly discovered ferromagnetic superconductor,…
The electronic structure of a-Fe1.06Te is studied with angle-resolved photoemission spectroscopy. We show that there is substantial spectral weight around Gamma and X, and lineshapes are intrinsically incoherent in the paramagnetic state.…
This paper reports the synthesis and superconducting behaviors of the tetragonal iron-chalcogenide superconductor FeSe. The electrical resistivity and magnetic moment measurements confirmed its superconductivity with a $T_c^{zero}$ and…
The ground state of the parent compounds of many high temperature superconductors is an antiferromagnetically (AFM) ordered phase, where superconductivity emerges when the AFM phase transition is suppressed by doping or application of…
We report the first photoemission study of Fe$_{1+x}$Te - the host compound of the newly discovered iron-chalcogenide superconductors (maximum T$_c$ $\sim$ 27K). Our results reveal a pair of nearly electron-hole compensated Fermi pockets,…
We investigate the chemical substitution of group 5 into BaFe2As2 (122) iron arsenide, in the effort to understand why Fe-site hole doping of this compound (e.g., using group 5 or 6) does not yield bulk superconductivity. We find an…