Upper critical fields and critical current density of single crystal

✍ Scribed by S.V. Chong; S. Hashimoto; K. Kadowaki

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 640 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.04.019

✦ Synopsis

The transport properties, upper critical fields, superconducting anisotropy, and critical current density of an iso-valent phosphorus-doped BaFe 2 As 2 single crystal close to optimum doping are investigated in this report. Temperature dependent resistivity and susceptibility show a superconducting transition temperature, T c , just below 31 K both with sharp transitions. The upper critical field parallel to the ab-plane, H c2 ab , is above 77 T while that along the c-axis direction, H c2 c , is just above 36 T, yielding a low superconducting anisotropy ratio ∼ 2. The estimated inter-plane coherence length based on the Ginzburg-Landau (G-L) theory indicates BaFe 2 (As 0.68 P 0.32 ) 2 is still above the point for a dimensional crossover inferring the superconducting layers are not weakly-coupled in this system. The critical current density at 5 K obtained from magnetization loops measurement show a modest J c as high as 10 5 A/cm 2 .