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arXiv 1907.04718cond-mat.supr-con
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超导CaKFe4As4中独特的缺陷结构和有利的涡旋钉扎特性

Unique defect structure and advantageous vortex pinning properties in superconducting CaKFe4As4

Shigeyuki Ishida, Akira Iyo, Hiraku Ogino, Hiroshi Eisaki, Nao Takeshita, Kenji Kawashima, Keiichi Yanagisawa, Yuuga Kobayashi, Koji Kimoto, Hideki Abe, Motohar… 展开作者

Shigeyuki Ishida, Akira Iyo, Hiraku Ogino, Hiroshi Eisaki, Nao Takeshita, Kenji Kawashima, Keiichi Yanagisawa, Yuuga Kobayashi, Koji Kimoto, Hideki Abe, Motoharu Imai, Jun-ichi Shimoyama, Michael Eisterer

摘要:

超导体的无损耗载流能力受其临界电流密度(Jc)的限制。提高Jc的现实应用的关键是工程缺陷结构,以优化钉扎景观。对于铁基超导体(IBS)被认为是高场应用的候选材料,高Jc值已通过各种技术来实现引入人工钉扎中心。在这里,我们报告了非凡的涡旋钉扎性能CaKFe4As4(CaK 1144)所产生的固有缺陷结构。扫描透射电子显微镜显示存在纳米级的共生体的CaFe2As2相,这是独特的CaK1144形成的线化合物。发现CaK 1144中的Jc性质与其他IBS不同,其特征在于相对于磁场取向的显著各向异性以及显著的钉扎机制随着温度的升高而显著增强。我们提出了一个全面的解释Jc属性的基础上独特的共生体作为钉扎中心。

英文摘要:

The lossless current-carrying capacity of a superconductor is limited by its critical current density (Jc). A key to enhance Jc towards real-life applications is engineering defect structures to optimize the pinning landscape. For iron-based superconductors (IBSs) considered as candidate materials for high-field applications, high Jc values have been achieved by various techniques to introduce artificial pinning centres. Here we report extraordinary vortex pinning properties in CaKFe4As4 (CaK1144) arising from the inherent defect structure. Scanning transmission electron microscopy revealed the existence of nanoscale intergrowths of the CaFe2As2 phase, which is unique to CaK1144 formed as a line compound. The Jc properties in CaK1144 are found to be distinct from other IBSs characterized by a significant anisotropy with respect to the magnetic field orientation as well as a remarkable pinning mechanism significantly enhanced with increasing temperature. We propose a comprehensive explanation of the Jc properties based on the unique intergrowths acting as pinning centres.

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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