Flux pinning properties in GdBCO coated conductors containing columnar defects with splay plane parallel to current direction

Furuki, Yuichi*; Sueyoshi, Tetsuro*; Kai, Takashi*; Iwanaga, Yasuya*; Fujiyoshi, Takanori*; Ishikawa, Norito   

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 Bc 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 Bc. 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.