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Awaji, Satoshi*; Namba, Masashi*; Watanabe, Kazuo*; Kai, Hideki*; Mukaida, Masashi*; Okayasu, Satoru
Journal of Applied Physics, 111(1), p.013914_1 - 013914_4, 2012/01
Times Cited Count:25 Percentile:69.54(Physics, Applied)The effect of -axis correlated pinning on the critical current density at low temperatures under high magnetic fields was investigated on the basis of the transport measurements of and irreversibility field B properties of an ErBaCuO film with inclined columnar defects. The contribution of correlated pinning on decreased drastically with decreasing temperature under high magnetic fields above the matching field. At low temperatures, the presence of a matching field limited the pinning force for correlated pinning, while the ratio of the maximum pinning force of the correlated pinning to the random one was proportional to the inverse of B. In order to improve the critical current properties at low temperatures under high magnetic fields, an increase in the matching field and/or the introduction of strong random pinning are effective.
Awaji, Satoshi*; Namba, Masashi*; Watanabe, Kazuo*; Ito, Shun*; Aoyagi, Eiji*; Kai, Hideki*; Mukaida, Masashi*; Okayasu, Satoru
IEEE Transactions on Applied Superconductivity, 21(3), p.3192 - 3195, 2011/06
Times Cited Count:5 Percentile:33.75(Engineering, Electrical & Electronic)The flux pinning behaviors for the heavy ion irradiated Er123 films are investigated based on the detailed (, , ) properties. The double peaks of curves for //c appear in case of the matching field of 0.3 T along -axis and 1.7 T tilted from -axis. In addition, the peaks on () at = 0 (B//c), which originate from the columnar defects, decrease with increasing magnetic field but increase again near the irreversibility field. We found that the cooperation model of the -axis correlated and random pinning centers can describe the observed double peak behavior of (B) and the angular dependence of related to the correlated pinning.