Bulk Superconductivity in Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ Induced by Annealing in Se and S Vapor

Abstract

We reported that bulk superconductivity in Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ can be induced by annealing in Se and S vapor. The well-annealed samples show a large critical current density, emph{J}$_c$ $\sim$ 2 - 4 $\times$ 10$^5$ A/cm$^2$. Combined with our previous reports about O$_2$ and Te annealing effects, we proved that bulk superconductivity can be successfully induced in Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ by annealing in atmosphere of all chalcogens, such as O, S, Se and Te.