Critical state models for flux‐pinning‐induced magnetostriction in type‐II superconductors
Critical state models for flux‐pinning‐induced magnetostriction in type‐II superconductors
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DOI：
10.1063/1.357249
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发表时间：
1994-10
影响因子：
3.2
通讯作者：
H. Ikuta;K. Kishio;K. Kitazawa
中科院分区：
文献类型：
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作者：
H. Ikuta;K. Kishio;K. Kitazawa
给出了II型超导体中磁通钉扎感生磁致伸缩的模型和计算结果。三种模型被认为是临界状态;原始Bean模型，Kim模型，和指数模型，其中的临界电流密度被假定为指数依赖于磁通密度。对于具有无限平板几何形状的试样，并假设总磁化强度的可逆部分小得可以忽略不计，导出了磁场下长度变化的解析表达式。结果用于计算机模拟和磁滞回线计算在很宽的范围内的相关参数。由于钉扎感生磁致伸缩直接揭示了钉扎力，因此每个模型的磁滞回线具有不同的特征，并进行了详细讨论。研究还表明，样品的钉扎力可以直接从磁致伸缩磁滞回线的宽度推断。最后，对高温超导体的实验结果进行了讨论，并与计算结果进行了比较。
Models and calculated results are presented for the flux‐pinning‐induced magnetostriction in type‐II superconductors. Three models are considered for the critical state; the original Bean model, the Kim model, and the exponential model in which the critical current density is assumed to depend exponentially on the flux density. The analytic expressions of the length change under the magnetic field are derived for specimens having infinite slab geometry and under the assumption that the reversible part of the total magnetization is negligibly small. The results are used for computer simulations and the hysteresis loops are calculated over a wide range of the relevant parameters. Since the pinning‐induced magnetostriction reveals the pinning force directly, the hysteresis loops for each model have different features which are discussed in detail. It is also shown that the pinning force of the sample can be directly inferred from the width of the magnetostriction hysteresis loop. Finally, the experimental results on high‐temperature superconductors are discussed in comparison with the calculated results.