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

• Published in: Solid state communications Vol. 152; no. 13; pp. 1135 - 1138
• Main Authors: Kawasaki, Yasuna, Deguchi, Keita, Demura, Satoshi, Watanabe, Tohru, Okazaki, Hiroyuki, Ozaki, Toshinori, Yamaguchi, Takahide, Takeya, Hiroyuki, Takano, Yoshihiko
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2012; Elsevier
• Subjects: A. FeTe1−xSex; B. O2-annealing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Magnetization; Exact sciences and technology; Magnetic properties; Phase diagrams; Physics; Properties of type I and type II superconductors; Superconductivity; A. FeTe1−xSex; D. Magnetization; B. O2-annealing; Antiferromagnetism; Phase diagrams; Annealing; Iron based superconductors; Magnetization; Magnetic ordering; B. O; Superconductivity; Controlled atmospheres; Magnetic susceptibility; Superconductors; Se; Temperature effects; Chemical composition; Iron Selenides tellurides; A. FeTe
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2012.04.002

Phase diagrams of as-grown and O2-annealed FeTe1−xSex 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 O2-annealed samples, complete suppression of magnetic order and the occurrence of bulk superconductivity were observed when x≥0.1. We found that O2-annealing induces bulk superconductivity for FeTe1−xSex. Oxygen probably plays a key role in the suppression of the magnetic order and the appearance of bulk superconductivity. ► Phase diagrams of as-grown and O2-annealed FeTe1−xSex determined from magnetic susceptibility measurement were obtained. ► For as-grown samples, weak superconductivity appeared when x≥0.1 and bulk superconductivity was established above x≥0.5. ► For O2-annealed samples, the occurrence of bulk superconductivity were observed when x≥0.1. ► We found that O2-annealing induces bulk superconductivity for FeTe1−xSex.