Boundaries of the instability region on the HT diagram of Nb thin films
Boundaries of the instability region on the HT diagram of Nb thin films
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DOI：
10.1088/0953-2048/21/4/045018
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发表时间：
2008-04-01
影响因子：
3.6
通讯作者：
Ortiz, W. A.
中科院分区：
文献类型：
--
作者：
Colauto, F.;Patino, E. J.;Ortiz, W. A.
在垂直几何形状的超导薄膜样品中，磁场以枝晶形式的灾难性穿透已经被报道。这种行为本质上与样品和基底吸收涡旋运动产生的热量的能力有关。为了映射不稳定性发生的区域，我们采用了直流磁强计，这已被证明是一种有效的技术，用于此目的。这种灾难性的状态在温度高于4K时停止。对于研究的样品，波动已被检测到的原始曲线的磁矩作为一个功能的应用领域。我们的系统研究表明，有一个阈值线的HT图上，其中包括磁响应波动的区域。
Catastrophic penetration of magnetic fields in the form of dendrites has been reported for some specimens of superconducting thin films in the perpendicular geometry. Such behavior is related essentially to the capability of the sample and substrate to assimilate heat generated by vortex motion. In order to map the region where instabilities occur, we have employed dc magnetometry, which has been shown to be an efficient technique for this purpose. This catastrophic regime ceases at temperatures above 4 K. For the sample studied, fluctuations have been detected on virgin curves of the magnetic moment as a function of the applied field. Our systematic study shows that there is a threshold line on the HT diagram, which encompasses the region where the magnetic response fluctuates.