Superconducting properties of highly oriented Fe1.03Te0.55Se0.45 with excess Fe

✍ Scribed by Junyi Ge; Shixun Cao; Shaoxi Shen; Shujuan Yuan; Baojuan Kang; Jincang Zhang

• Book ID: 104093897
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 849 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.06.033

✦ Synopsis

Highly oriented Fe 1.03 Te 0.55 Se 0.45 crystal with T c ∼ 14.4 K was grown through Optical Zone-Melting Technique. Resistivity versus temperature under various magnetic fields was measured. The upper critical field µ 0 H c2 estimated from the WHH equation reaches 42.6 T, which is in good agreement with experimental results. The Ginzburg-Landau (GL) coherence length at zero temperature was estimated to be 27.77-29.33 Å. The activation energy determined from the Arrhenius dependence of the resistivity reaches ∼ 10 3 K. Due to its relatively low T c compared with FeAs superconductors and high-T c cuprates, we suggest that the high activation energy should be attributed to the existence of excess Fe located in FeTe(Se) layers, which might induce vacancies into the system. The e-ph coupling parameter is estimated to be 1.40, revealing that Fe 1.03 Te 0.55 Se 0.45 belongs to the strong electron-phonon coupling system.