C-axis correlated pinning mechanism in vortex liquid and solid phases for Sm123 film with well-aligned BaHfO3 nanorods
C-axis correlated pinning mechanism in vortex liquid and solid phases for Sm123 film with well-aligned BaHfO3 nanorods
复制标题
具有良好排列的 BaHfO3 纳米棒的 Sm123 薄膜在涡流液相和固相中的 C 轴相关钉扎机制
DOI：
10.1088/1361-6668/aa8d10
复制
发表时间：
2017
影响因子：
3.6
通讯作者：
Matsumoto Kaname
中科院分区：
文献类型：
--
作者：
Awaji Satoshi;Tsuchiya Yuji;Miura Shun;Ichino Yusuke;Yoshida Yutaka;Matsumoto Kaname
纳米棒是一种纳米尺度的柱状沉淀物，近年来被用来提高REBa 2Cu 3 Oy（RE 123，RE：稀土元素）高温超导带材/薄膜在磁场中的临界电流密度Jc。然而，纳米棒的磁通钉扎机制尚不清楚。详细研究了具有5.6vol%BaHfO3纳米棒的高质量Sm 123薄膜的Jc和电阻率ρ特性，并在磁通钉扎状态图的基础上讨论了其磁通钉扎特性.在离域温度以上的高温下，Jc和ρ的场依赖性出现平台。这表明纳米棒钉扎在涡旋液相中变得有效，并且当温度朝向离域温度降低时，纳米棒钉扎长大。在离域温度以上的高温区的“多纳米棒”状态下，由于纳米棒钉扎和随机钉扎的共存，Fp曲线出现双峰。然而，在低于70 K的低温下，在低场和温度相关的（非标度）归一化Fp曲线的尺度Fp曲线观察。利用随机钉扎中心和相关钉扎中心的协同模型进行详细分析，发现在匹配场下，纳米棒钉扎是主要的钉扎中心，而在匹配场下，纳米棒钉扎和随机钉扎的协同作用决定了高场Jc特性.
Nanorods, which are nano-scaled columnar-shape precipitates, have recently been used to improve critical current density J c in magnetic fields for REBa 2 Cu 3 O y (RE123, RE: rare earth element) high temperature superconducting tapes/films. However, the flux pinning mechanism of the nanorod is not clear yet. We investigated the J c and resistivity ρ properties in detail and discussed the flux pinning properties on the basis of the flux pinning state diagram for high-quality Sm123 films with well-aligned 5.6 vol% BaHfO 3 nanorods. Plateaus were observed in the field dependence of J c and ρ at high temperatures above the delocalization temperature. This suggests that nanorod pinning becomes effective in the vortex liquid phase and it grows up when the temperature decreases toward the delocalization temperature. In the'many-nanorod'state in the high temperature region above the delocalization temperature, double peaks in the F p curves appear due to the coexistence of nanorod pinning and random pinning. At low temperatures below 70 K, however, the well-scaled F p curves at low fields and temperature dependent (non-scaled) normalized F p curves are observed. From detailed analysis using the cooperation model of the random and the correlated pinning centers, we found that nanorod pinning is dominant below the matching field and the cooperation between nanorod pinning and random pinning determines the high field J c properties above the matching field.