Related papers: The Stoichiometry of FeSe
The FeSe-based superconductors exhibit a wide range of critical temperature Tc under a variety of material and physical conditions, but extensive studies to date have yet to produce a consensus view on the underlying mechanism. Here we…
We present ARPES data taken from the structurally simplest representative of iron-based superconductors, FeSe, in a wide temperature range. Apart from the variations related to the nematic transition, we detect very pronounced shifts of the…
The discovery of high-temperature (Tc) superconductivity in monolayer FeSe on SrTiO3 raised a fundamental question whether high Tc is commonly realized in monolayer iron-based superconductors. Tetragonal FeS is a key material to resolve…
Engineering heterostructures with various types of quantum materials can provide an intriguing playground for studying exotic physics induced by the proximity effect. Here, we report the successful synthesis of iron-based superconductor…
A very fundamental and unconventional characteristic of superconductivity in iron-based materials is that it occurs in the vicinity of {\it two} other instabilities. Apart from a tendency towards magnetic order, these Fe-based systems have…
The structural and electronic properties of FeSe ultra-thin layers on Bi$_{2}$Se$_{3}$ have been investigated with a combination of scanning tunneling microscopy and spectroscopy and angle-resolved photoemission spectroscopy. The FeSe…
The ternary iron arsenide BaFe2As2 with the tetragonal ThCr2Si2-type structure exhibits a spin density wave (SDW) anomaly at 140 K, very similar to LaFeAsO, the parent compound of the iron arsenide superconductors. BaFe2As2 is a poor…
We prepare single layer potassium-doped iron selenide (110) film by molecular beam expitaxy. Such a single layer film can be viewed as a two-dimensional system composed of weakly coupled two-leg iron ladders. Scanning tunneling spectroscopy…
In this letter we show that superconducting Fe1.01Se undergoes a structural transition at 90 K from a tetragonal to an orthorhombic phase but that non-superconducting Fe1.03Se does not. Further, high resolution electron microscopy study at…
The optical properties of the iron-chalcogenide superconductor K{0.8}Fe{2-y}Se2, with a critical temperature Tc = 31 K, have been measured over a wide frequency range in the a-b planes above and below Tc. The conductivity is incoherent at…
At present, metal hydrides are considered highly promising materials for phonon-mediated superconductors, that exhibit high values of the critical temperature. In the present study, the superconducting properties of the compressed selenium…
Unlike the parent phases of the iron-arsenide high Tc superconductors, undoped FeSe is not magnetically ordered and exhibits superconductivity with Tc~9K. Equally surprising is the fact that applied pressure dramatically enhances the modest…
The discovery of superconductivity in alkali-ammonia co-intercalated FeSe has generated intensive interest because of their highest Tc (~ 45 K) among iron-chalcogenide superconductors with bulk form. Here, we report the phase diagrams of…
There is an ongoing debate about the relative importance of structural change versus doping charge carriers on the mechanism of superconductivity in Fe-based materials. Elucidating this issue is a major challenge since it would require a…
Superconducting FeSe has been investigated by measurements of the magnetic susceptibility versus temperature and Moessbauer spectroscopy at various temperatures including strong external magnetic fields applied to the absorber. It was found…
The structurally simplest Fe-based superconductor FeSe with a critical temperature $T_{c}\approx$ 8.5 K displays a breaking of the four-fold rotational symmetry at a temperature $T_{s}\approx 87$ K. We investigated the electronic properties…
57Fe Moessbauer spectroscopy was applied to investigate the superconductor parent compound Fe(1+x)Te for x=0.06, 0.10, 0.14, 0.18 within the temperature range 4.2 K - 300 K. A spin density wave (SDW) within the iron atoms occupying regular…
Unlike the widely studied ReFeAsO series, the newly discovered iron-based superconductor ThFeAsN exhibits a remarkably high critical temperature of 30 K, without chemical doping or external pressure. Here we investigate in detail its…
A number of recent experiments indicate that the iron-chalcogenide FeSe provides the long-sought possibility to study bulk superconductivity in the cross-over regime between the weakly coupled Bardeen--Cooper--Schrieffer (BCS) pairing and…
To study the microscopic electronic and magnetic interactions in the substoichiometric iron chalcogenide FeSe$_{1-x}$ which is observed to superconduct at x~1/8 up to $T_c$=27 K, we use first principles methods to study the Se vacancy in…