BaFe2(As1−xPx)2 (x = 0.22−0.42) thin films grown on practical metal–tape substrates and their critical current densities. (10th March 2017)

• Record Type: Journal Article
• Authors: Hiramatsu, Hidenori; Sato, Hikaru; Kamiya, Toshio; Hosono, Hideo
• Is Part Of: Superconductor science & technology. Volume 30:Number 4(2017:Apr.)
• Publication Date: 2017-03-10
• Subjects: Fe-based superconductors -- thin film -- coated conductor; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aa621c
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: We optimized the substrate temperature ( T s ) and phosphorus concentration ( x ) of BaFe2 (As1− x P x )2 films on practical metal–tape substrates for pulsed laser deposition from the viewpoints of crystallinity, superconductor critical temperature ( T c ), and critical current density ( J c ). It was found that the optimum T s and x values are 1050 °C and x = 0.28, respectively. The optimized film exhibits T c onset = 26.6 and T c zero = 22.4 K along with a high self-field J c at 4 K (∼1 MA cm −2 ) and relatively isotropic J c under magnetic fields up to 9 T. Unexpectedly, we found that lower crystallinity samples, which were grown at a higher T s of 1250 °C than the optimized T s = 1050 °C, exhibit higher J c along the ab plane under high magnetic fields than the optimized samples. The presence of horizontal defects that act as strong vortex pinning centers, such as stacking faults, are a possible origin of the high J c values in the poor crystallinity samples.