Phase diagram and oxygen annealing effect of FeTe1−Se iron-based superconductor

Abstract

Phase diagrams of as-grown and O 2 -annealed FeTe 1-x Se x determined from magnetic susceptibility measurement were obtained. For as-grown samples, the antiferromagnetic order was fully suppressed in the range region x ≥ 0.15, and weak superconductivity appeared when x ≥ 0.1.Beginning at x = 0.5, weak superconductivity was found to evolve into bulk superconductivity.Interestingly, for O 2 -annealed samples, complete suppression of magnetic order and the occurrence of bulk superconductivity were observed when x ≥ 0.1. We found that O 2 -annealing induces bulk superconductivity for FeTe 1-x Se x . Oxygen probably plays a key role in the suppression of the magnetic order and the appearance of bulk superconductivity.

Multiband effects and possible Dirac fermions inFe1+yTe0.6Se0.4Sun1, Taen2, Yamada3 et al. 2014Phys. Rev. B628481View full textAdd to dashboardCite

“…However, in iron-chalcogenide FeTe 0.6 Se 0.4 , the long-range SDW is already totally suppressed according to the phase diagram, 56,57 which indicates the origin of the Dirac cone state in iron-chalcogenides may be different from that in iron pnictides. Here, we should point out that although the long-range SDW is proven to be suppressed by Se doping, the SDW fluctuation may still survive.…”

Physics and chemistry of layered chalcogenide superconductors

“…Only the oxygen-annealed sample shows a distinct superconducting behavior. Kawasaki et al [70] reported that annealing in oxygen is effective for not only FeTe 1-x S x but also FeTe 1-x Se x . Figure 13 shows the temperature dependence of magnetic susceptibility for Next, we discuss the relation between bulk superconductivity and antiferromagnetic fluctuations.…”

Superconductivity and magnetism in 11-structure iron chalcogenides in relation to the iron pnictides

“…Within a picture of spin-fluctuation mediated superconductivity a susceptibility peaked at the connection vector [47,50], while the right side shows the behavior of Fe 1+δ Te x Se 1−x as a function of x following [47,103,104] Superconductivity can also be produced by alloying with FeS [105,106].…”