Removal of excess iron by annealing processes and emergence of bulk superconductivity in sulfur-substituted FeTe

Abstract

There are several strategies to discover new superconductors. Growing new materials and applying high pressures can be the classic ways since superconductivity was found. Also, chemical processing, such as annealing, is another way to induce superconductivity in a non-superconducting material. Here, we show chemical processing effects in the non-superconducting material, sulfur-substituted FeTe. It has been known that superconductivity in S-substituted FeTe is induced by O${}_2$ annealing. We revealed that hydrochloric acid etching and vacuum annealing for O${}_2$-annealed samples made the quality of superconductivity higher by several physical property measurements. Furthermore, we visualized the superconducting regions by a magneto-optical imaging technique, indicating that the superconductivity in the processed sample was bulk. In this sample, we confirmed that the concentration of excess iron was reduced compared to that in the as-grown state. These results provide an important route to bulk superconductivity in S-substituted FeTe and its related iron-based compounds.

Accepted in Phys. Rev. Mater

References in corpus (17)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Density functional study of FeS, FeSe and FeTe: Electronic structure, magnetism, phonons and superconductivity
• First-order magnetic and structural phase transitions in Fe${}_{1+y}$Se${}_x$Te${}_{1-x}$
• Dynamics and mechanism of oxygen annealing in Fe${}_{1+y}$Te${}_{0.6}$Se${}_{0.4}$ single crystal
• FeTe as a candidate material for new iron-based superconductor
• Multiband Effect and Possible Dirac Fermions in Fe${}_{1+y}$Te${}_{0.6}$Se${}_{0.4}$
• Evolution of superconductivity by oxygen annealing in FeTe0.8S0.2
• Strong correlation and massive spectral-weight redistribution induced spin density wave in a-Fe1.06Te
• Superconductivity in oxygen-annealed FeTe1-xSx single crystal
• Unconventional fully-gapped superconductivity in the heavy-fermion metal CeCu${}_2$Si${}_2$
• Hexadecapole fluctuation mechanism for s-wave heavy fermion superconductor CeCu2Si2: Interplay between intra- and inter-orbital Cooper pairs
• Anisotropic Fully-Gapped Superconductivity Possibly Mediated by Charge Fluctuations in a Nondimeric Organic Complex
• Single crystal growth and structural characterization of FeTe1-xSx
• Pseudogap formation in organic superconductors
• Bulk superconductivity in FeTe${}_{1-x}$Se${}_x$ via physicochemical pumping of excess iron
• Size Dependence of Oxygen-annealing Effects on Superconductivity of Fe{1+y}Te{1-x}S{x}
• Dynamic Evolution of Flux Distributions in a Pulse-driven Superconductor by High-speed Magneto-optical Imaging