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arXiv 0811.1253cond-mat.supr-concond-mat.str-el
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用双带超导理论系统表征MgB $_2$薄膜的上临界场

Systematic characterization of upper critical fields for MgB$_2$ thin films using the two-band superconducting theory

S. Noguchi, A. Kuribayashi, T. Ishida, T. Oba, H. Iriuda, M. Yoshizawa, Y. Harada, S. Miki, H. Shimakage, Z. Wang, K. Satoh, T. Yotsuya

摘要:

本文给出了用分子束外延、多靶溅射和共蒸发沉积方法制备的$_2$薄膜的上临界场$H_{\rm c2}$的实验结果。在$D_π/D_σ>1$的情况下,通过应用脏双带超导的Gurevich理论成功地分析了$H_{\rm c2}(T)$的实验数据,其中$D_π$和$D_σ$分别是$π$和$σ$带的带内电子扩散系数。我们发现,从分析得到的参数是强烈相关的超导转变温度$T_{\rm c}$的薄膜。我们还讨论了由磁电阻测量证实的中温相变宽度的反常变窄。

英文摘要:

We present experimental results of the upper critical fields $H_{\rm c2}$ of various MgB$_2$ thin films prepared by the molecular beam epitaxy, multiple-targets sputtering, and co-evaporation deposition apparatus. Experimental data of the $H_{\rm c2}(T)$ are successfully analyzed by applying the Gurevich theory of dirty two-band superconductivity in the case of $D_π/D_σ>1$, where $D_π$ and $D_σ$ are the intraband electron diffusivities for $π$ and $σ$ bands, respectively. We find that the parameters obtained from the analysis are strongly correlated to the superconducting transition temperature $T_{\rm c}$ of the films. We also discuss the anormalous narrowing of the transition width at intermediate temperatures confirmed by the magnetoresistance measurements.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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