TY - JOUR
T1 - Angular behaviour of critical current density in YBa2Cu3Oy thin films with crossed columnar defects
AU - Sueyoshi, T.
AU - Sogo, T.
AU - Nishimura, T.
AU - Fujiyoshi, T.
AU - Mitsugi, F.
AU - Ikegami, T.
AU - Awaji, S.
AU - Watanabe, K.
AU - Ichinose, A.
AU - Ishikawa, N.
N1 - Funding Information:
This work was supported by KAKENHI (21760236, 23760288, 25420292) from the Japan Society for the Promotion of Science and was performed by the Common-Use Facility Program of JAEA. A part of this work was performed at High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University.
Publisher Copyright:
© 2016 IOP Publishing Ltd.
PY - 2016/5/12
Y1 - 2016/5/12
N2 - Columnar defects (CDs) were installed into YBa2Cu3Oy thin films at the crossing angle ± θ i relative to the c-axis using 200 MeV Xe ions, in order to clarify the influence of ± θ i on the angular behaviours of critical current density J c. The width of a J c peak occuring at B || c linearly increases with broadening CD-crossing angle, where its shape maintains a single peak in the range of θ i ≤ ± 25°. The CDs crossing at ± 45°, on the other hand, drastically change the angular behaviour of J c around B || c: the J c is equally elevated over the angular region from -45° to 45° in the lower magnetic field, whereas the rapid reduction of the J c occurs at B || c with increasing magnetic field, leading to the appearance of double peaks near the irradiation angles, ± 45°. This crossover phenomenon is attributed to the difference in the pinned states of flux lines between B || c and at the irradiation angles: the CDs crossing at ± 45° cannot provide the correlated flux pinning along the c-axis, resulting in the uncorrelated pinned state at B || c.
AB - Columnar defects (CDs) were installed into YBa2Cu3Oy thin films at the crossing angle ± θ i relative to the c-axis using 200 MeV Xe ions, in order to clarify the influence of ± θ i on the angular behaviours of critical current density J c. The width of a J c peak occuring at B || c linearly increases with broadening CD-crossing angle, where its shape maintains a single peak in the range of θ i ≤ ± 25°. The CDs crossing at ± 45°, on the other hand, drastically change the angular behaviour of J c around B || c: the J c is equally elevated over the angular region from -45° to 45° in the lower magnetic field, whereas the rapid reduction of the J c occurs at B || c with increasing magnetic field, leading to the appearance of double peaks near the irradiation angles, ± 45°. This crossover phenomenon is attributed to the difference in the pinned states of flux lines between B || c and at the irradiation angles: the CDs crossing at ± 45° cannot provide the correlated flux pinning along the c-axis, resulting in the uncorrelated pinned state at B || c.
KW - columnar defects
KW - critical current density
KW - flux pinning
KW - irradiation
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U2 - 10.1088/0953-2048/29/6/065023
DO - 10.1088/0953-2048/29/6/065023
M3 - Article
AN - SCOPUS:84969776930
VL - 29
JO - Superconductor Science and Technology
JF - Superconductor Science and Technology
SN - 0953-2048
IS - 6
M1 - 065023
ER -