2017/03/10 by Hidenori Hiramatsu, Hikaru Sato, Toshio Kamiya +1
Chemistry · Materials Science · Physics and Astronomy · #Analytical Chemistry (journal) #Chemistry #Composite material #Condensed matter physics #Critical current #Crystallinity #Crystallite #Crystallography #Degree (music) #Iron-based superconductors research #Materials science #Metallurgy #Nanotechnology #Nuclear magnetic resonance #Physics #Physics of Superconductivity and Magnetism #Pulsed laser deposition #Rare-earth and actinide compounds #Stacking #Substrate (aquarium) #Superconductivity #Thin film #cond-mat.supr-con
paper · pdf · doi:10.1088/1361-6668/aa621c
published as Supercond. Sci. Technol. 30 (2017) 044003
openalex publication_date 2017/03/10 · openalex created_date 2017/03/16 · arxiv created 2017/03/19 · arxiv updated 2017/03/21 · openalex updated_date 2026/08/05
Abstract We optimized the substrate temperature ( T s ) and phosphorus concentration ( x ) of BaFe 2 (As 1− 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mi mathvariant="normal">onset</mml:mi> </mml:mrow> </mml:msup> <mml:mo>=</mml:mo> <mml:mn>26.6</mml:mn> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:msub> <mml:mrow> <mml:mi>T</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">c</mml:mi> </mml:mrow> </mml:msub> <mml:mrow> <mml:mi mathvariant="normal">zero</mml:mi> </mml:mrow> </mml:msup> <mml:mo>=</mml:mo> <mml:mn>22.4</mml:mn> <mml:mspace width=".25em"/> <mml:mi mathvariant="normal">K</mml:mi> </mml:math> 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.