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Sueyoshi, Tetsuro*; Kotaki, Tetsuya*; Furuki, Yuichi*; Fujiyoshi, Takanori*; Semboshi, Satoshi*; Ozaki, Toshinori*; Sakane, Hitoshi*; Kudo, Masaki*; Yasuda, Kazuhiro*; Ishikawa, Norito
Japanese Journal of Applied Physics, 59(2), p.023001_1 - 023001_7, 2020/02
Times Cited Count:8 Percentile:34.47(Physics, Applied)We show that Xe ion irradiation with 80 MeV to GdBaCu
Oy-coated conductors creates different morphologies of columnar defects (CDs) depending on the irradiation angles relative to the c-axis: continuous CDs with a larger diameter are formed for oblique irradiation at
= 45
, whereas the same ion beam at a different angle (
= 0
) induces the formation of discontinuous CDs. The direction-dependent morphologies of CDs significantly affect the angular behavior of the critical current density
.
Furuki, Yuichi*; Sueyoshi, Tetsuro*; Kai, Takashi*; Iwanaga, Yasuya*; Fujiyoshi, Takanori*; Ishikawa, Norito
Physica C, 518, p.58 - 62, 2015/11
Times Cited Count:6 Percentile:26.09(Physics, Applied)In order to reveal the influence of crossing angle of one-dimensional pinning centers on angular dependence of critical current density Jc, heavy-ion irradiation was performed to introduce columnar defects (CDs) crossing relative to the c-axis into GdBCO coated conductors, where the splay plane consisting of the two directions of CDs is parallel to the current flow direction. For the sample containing CDs with 15, a single and sharp peak was observed around B
c in the angular dependence of Jc. When the crossing angle was extended to 45
, the single Jc-peak became broader, which was a gently-sloping mountain-like shape centered at B
c. For 75
, on the other hand, a quite different behaviour of Jc from the other irradiated samples was observed, which was analogous to the angular dependence of Jc typical of three dimensional pinning centers.
Sueyoshi, Tetsuro*; Kotaki, Tetsuya*; Furuki, Yuichi*; Uraguchi, Yusei*; Kai, Takashi*; Fujiyoshi, Takanori*; Shimada, Yusuke*; Yasuda, Kazuhiro*; Ishikawa, Norito
IEEE Transactions on Applied Superconductivity, 25(3), p.6603004_1 - 6603004_4, 2015/06
Times Cited Count:12 Percentile:50.69(Engineering, Electrical & Electronic)To investigate the effect of discontinuity of 1-D pinning centers on the flux pinning in a wide range of magnetic field directions, discontinuous columnar defects (CDs) and continuous CDs were formed in GdBCO coated conductors using Xe-ion irradiations with 80 and 270 MeV, respectively. An overall shift upward in Jc, for the 80-MeV-irradiated sample compared to the 270-MeV-irradiated one, can be observed in every direction of magnetic field, which is more remarkable as temperature decreases. This implies a synergetic effect of the pinning interaction between the linearity and the discontinuity for the discontinuous CDs.
Sueyoshi, Tetsuro*; Furuki, Yuichi*; Tanaka, Eiki*; Fujiyoshi, Takanori*; Mitsugi, Fumiaki*; Ikegami, Tomoaki*; Ishikawa, Norito
IEEE Transactions on Applied Superconductivity, 23(3), p.8002404_1 - 8002404_4, 2013/06
Times Cited Count:8 Percentile:40.67(Engineering, Electrical & Electronic)To investigate whether one dimensional pinning centers (1D PCs) can attain the isotropic critical current density () properties, columnar defects (CDs) crossing at widespread angles were installed by heavy-ion irradiations into YBCO thin films. For the sample containing the CDs crossing relative to the
-axis, the plateau-like behavior of
is realized over a wide range of magnetic field orientations, except for around B
-plane where a dip structure is accompanied by a rapid decline of the
. For the bimodal splay configuration consisting of CDs crossing relative to the
-axis, a single peak around the
-axis is observed in the angular dependence of
, suggesting the splay effect at B
-axis by the crossed CDs. Two parallel families of CDs crossing relative to the
-plane, on the other hand, bring about not a peak but a dip around B
-plane on the angular dependence of
.