TY - JOUR
T1 - Current Flow and Flux Pinning Properties of YBCO Foam Struts
AU - Koblischka, Michael R.
AU - Koblischka-Veneva, Anjela
AU - Berger, Kévin
AU - Nouailhetas, Quentin
AU - Douine, Bruno
AU - Reddy, E. S.
AU - Schmitz, Georg J.
N1 - Funding Information:
This work was supported by the SUPERFOAM international project funded by ANR and DFG under Grant ANR-17-CE05-0030 and Grant DFG-ANR Ko2323-10.
Funding Information:
Manuscript received October 25, 2018; accepted January 17, 2019. Date of publication January 23, 2019; date of current version February 11, 2019. This work was supported by the SUPERFOAM international project funded by ANR and DFG under Grant ANR-17-CE05-0030 and Grant DFG-ANR Ko2323-10. (Corresponding author: Michael R. Koblischka.) M. R. Koblischka and A. Koblischka-Veneva are with the Experimental Physics, Saarland University, Saarbrücken 66041, Germany, and also with the Department of Materials Science and Engineering, Shibaura Institute of Technology, Tokyo 135-8548, Japan (e-mail:,m.koblischka@mx.uni-saarland.de).
Publisher Copyright:
© 2018 IEEE.
PY - 2019/8
Y1 - 2019/8
N2 - The current flow and the flux pinning properties on struts of superconducting YBa 2 Cu 3 O x foams are analyzed in detail in the temperature range 60 K ≤ T ≤ T c . For this purpose, magnetization loops were measured on foam struts taken from various positions of a 5 × 2 × 2 cm 3 large foam sample prepared at RWTH Aachen. From these data, the critical current densities, j c , and the flux pinning forces, F p = j c × B, were calculated and pinning force scaling diagrams F p /F p ,max versus h = H a /H irr were established. The scaling in the temperature range 60 K < T < 90 K was found to be well developed for all samples with peak positions, h 0 , above 0.4, which is an indication of δT c -pinning. The shape of the pinning functions is found to be completely different from all other high-T c materials and varies only slightly with position. This specific dome shape cannot be described by an addition of several pinning functions, and the parameters p and q do not fit to the description of Dew-Hughes. Therefore, we employ Kramer plots to obtainmore information on the flux pinning mechanism.
AB - The current flow and the flux pinning properties on struts of superconducting YBa 2 Cu 3 O x foams are analyzed in detail in the temperature range 60 K ≤ T ≤ T c . For this purpose, magnetization loops were measured on foam struts taken from various positions of a 5 × 2 × 2 cm 3 large foam sample prepared at RWTH Aachen. From these data, the critical current densities, j c , and the flux pinning forces, F p = j c × B, were calculated and pinning force scaling diagrams F p /F p ,max versus h = H a /H irr were established. The scaling in the temperature range 60 K < T < 90 K was found to be well developed for all samples with peak positions, h 0 , above 0.4, which is an indication of δT c -pinning. The shape of the pinning functions is found to be completely different from all other high-T c materials and varies only slightly with position. This specific dome shape cannot be described by an addition of several pinning functions, and the parameters p and q do not fit to the description of Dew-Hughes. Therefore, we employ Kramer plots to obtainmore information on the flux pinning mechanism.
KW - Foam
KW - YBCO
KW - critical currents
KW - flux pinning
KW - scaling
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U2 - 10.1109/TASC.2019.2894712
DO - 10.1109/TASC.2019.2894712
M3 - Article
AN - SCOPUS:85061635593
VL - 29
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
SN - 1051-8223
IS - 5
M1 - 8624451
ER -