Superconductivity close to magnetic instability in Fe ( Se 1 − x Te x ) 0.82

We report our study of the evolution of superconductivity and the phase diagram of the ternary $\text{Fe}{({\text{Se}}_{1\ensuremath{-}x}{\text{Te}}_{x})}_{0.82}$ $(0\ensuremath{\le}x\ensuremath{\le}1.0)$ system. We discovered a superconducting phase with ${T}_{c,\text{max}}=14\text{ }\text{K}$ in the $0.3<x<1.0$ range. This superconducting phase is suppressed when the sample composition approaches the end member ${\text{FeTe}}_{0.82}$, which exhibits an incommensurate antiferromagnetic order. We discuss the relationship between the superconductivity and magnetism of this material system in terms of recent results from neutron-scattering measurements. Our results and analyses suggest that…