Enhanced critical current in superconducting FeSe0.5Te0.5 films at all magnetic field orientations by scalable gold ion irradiation. (17th January 2018)

• Record Type: Journal Article
• Authors: Ozaki, Toshinori; Wu, Lijun; Zhang, Cheng; Si, Weidong; Jie, Qing; Li, Qiang
• Is Part Of: Superconductor science & technology. Volume 31:Number 2(2018:Feb.)
• Publication Date: 2018-01-17
• Subjects: iron-based superconductor -- thin film -- irradiation -- critical temperature -- critical current density -- vortex pinning; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aaa3c4
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: The loss-less electrical current-carrying capability of type II superconductors, measured by the critical current density J c, can be increased by engineering desirable defects in superconductors to pin the magnetic vortices. Here, we demonstrate that such desirable defects can be created in superconducting FeSe0.5 Te0.5 films by 6 MeV Au-ions irradiations that produce cluster-like defects with sizes of 10–15 nm over the entire film. The pristine FeSe0.5 Te0.5 film exhibits a low anisotropy in the angular dependence of J c . A clear improvement in the J c is observed upon Au-ion irradiation for all field orientations at 4.2 K. Furthermore, a nearly 70% increase in J c is observed at a magnetic field of 9 T applied parallel to the crystallographic c -axis at 10 K with little reduction of the superconducting transition temperature T c . Our studies show that a dose of 1 × 10 12 Au cm –2 irradiation at a few MeV is sufficient in order to provide a strong isotropic pinning defect landscape in iron-based superconducting films.