Fabrication of iron-based superconducting tapes using Ba1−xKxFe2As2 with x = 0.3 and 0.4. (27th March 2017)

• Record Type: Journal Article
• Authors: Ishida, S; Taira, H; Ishii, A; Asou, T; Itou, S; Nishio, T; Tsuchiya, Y; Iyo, A; Eisaki, H; Matsuzaki, K; Yoshida, Y
• Is Part Of: Superconductor science & technology. Volume 30:Number 5(2017:May)
• Publication Date: 2017-03-27
• Subjects: iron-based superconductors -- Ba1−xKxFe2As2 -- doping level -- superconducting wires and tapes -- powder-in-tube method -- critical current density; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aa62d4
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: We fabricated iron-based superconducting tapes by using Ba1− x K x Fe2 As2 with different potassium concentrations ( x = 0.3 and 0.4) and the powder-in-tube method, and we studied their superconducting properties. The temperature ( T ) dependence of magnetization of the x = 0.3 tape showed a sharper superconducting transition compared with the x = 0.4 tape. Moreover, the x = 0.3 tape showed a high value of transport J c exceeding 10 5 A cm −2 at T = 4.2 K and self-field, demonstrating the high potential of the x = 0.3 tape. On the other hand, the x = 0.4 tape showed larger J c values in higher fields ( μ 0 H > 0.5 T) reaching 5.0 × 10 4 A cm −2 at μ 0 H = 3 T, which is attributed to improved grain connectivity. In the scanning electron microscope images, we observed cracks and voids in the superconducting cores, which are likely to limit their performance. Further enhancement of J c is expected by improving the grain connectivity of the superconducting cores through the optimization of the fabrication and heat treatment processes, especially for the x = 0.3 tape.