Maiorov B, Baily S A, Zhou H, Ugurlu O, Kennison J A, Dowden P C, Holesinger T G, Foltyn S R, Civale L
Superconductivity Technology Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Nat Mater. 2009 May;8(5):398-404. doi: 10.1038/nmat2408. Epub 2009 Apr 6.
Retaining a dissipation-free state while carrying large electrical currents is a challenge that needs to be solved to enable commercial applications of high-temperature superconductivity. Here, we show that the controlled combination of two effective pinning centres (randomly distributed nanoparticles and self-assembled columnar defects) is possible and effective. By simply changing the temperature or growth rate during pulsed-laser deposition of BaZrO(3)-doped YBa(2)Cu(3)O(7) films, we can vary the ratio of these defects, tuning the field and angular critical-current (Ic) performance to maximize Ic. We show that the defects' microstructure is governed by the growth kinetics and that the best results are obtained with a mixture of splayed columnar defects and random nanoparticles. The very high Ic arises from a complex vortex pinning landscape where columnar defects provide large pinning energy, while splay and nanoparticles inhibit flux creep. This knowledge is used to produce thick films with remarkable Ic(H) and nearly isotropic angle dependence.
在承载大电流时保持无耗散状态是实现高温超导商业化应用需要解决的一个挑战。在此，我们表明两种有效钉扎中心（随机分布的纳米颗粒和自组装柱状缺陷）的可控组合是可行且有效的。通过在脉冲激光沉积掺BaZrO(3)的YBa(2)Cu(3)O(7)薄膜过程中简单改变温度或生长速率，我们可以改变这些缺陷的比例，调整磁场和角度临界电流（Ic）性能以最大化Ic。我们表明缺陷的微观结构受生长动力学支配，并且以张开的柱状缺陷和随机纳米颗粒的混合物可获得最佳结果。非常高的Ic源自复杂的涡旋钉扎态势，其中柱状缺陷提供大的钉扎能量，而张开和纳米颗粒抑制磁通蠕动。这一知识被用于制备具有显著Ic(H)和近乎各向同性角度依赖性的厚膜。
