最佳掺杂（Ba，K）Fe2As2单晶在静水压力下的磁通钉扎机制研究。

Study of flux pinning mechanism under hydrostatic pressure in optimally doped (Ba,K)Fe2As2 single crystals.

作者信息

Shabbir Babar, Wang Xiaolin, Ma Y, Dou S X, Yan S S, Mei L M

机构信息

Spintronic and Electronic Materials Group, Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong, NSW 2522, Australia.

Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, 2703, Beijing 100190, P. R. China.

出版信息

Sci Rep. 2016 Mar 17;6:23044. doi: 10.1038/srep23044.

DOI:10.1038/srep23044

PMID:26983500

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4794803/

Abstract

Strong pinning depends on the pinning force strength and number density of effective defects. Using the hydrostatic pressure method, we demonstrate here that hydrostatic pressure of 1.2 GPa can significantly enhance flux pinning or the critical current density (Jc) of optimally doped Ba0.6K0.4Fe2As2 crystals by a factor of up to 5 in both low and high fields, which is generally rare with other Jc enhancement techniques. At 4.1 K, high pressure can significantly enhance Jc from 5 × 10(5 )A/cm(2) to nearly 10(6 )A/cm(2) at 2 T, and from 2 × 10(5 )A/cm(2) to nearly 5.5 × 10(5 )A/cm(2) at 12 T. Our systematic analysis of the flux pinning mechanism indicates that both the pinning centre number density and the pinning force are greatly increased by the pressure and enhance the pinning. This study also shows that superconducting performance in terms of flux pinning or Jc for optimally doped superconducting materials can be further improved by using pressure.

摘要

强钉扎取决于钉扎力强度和有效缺陷的数密度。我们在此采用静水压力法证明，1.2吉帕的静水压力能够显著增强最佳掺杂的Ba0.6K0.4Fe2As2晶体的磁通钉扎或临界电流密度（Jc），在低场和高场中增强倍数高达5倍，这在其他Jc增强技术中较为罕见。在4.1 K时，高压可使2 T下的Jc从5×10⁵ A/cm²显著提高到近10⁶ A/cm²，在12 T时从2×10⁵ A/cm²提高到近5.5×10⁵ A/cm²。我们对磁通钉扎机制的系统分析表明，压力使钉扎中心数密度和钉扎力都大幅增加，从而增强了钉扎作用。该研究还表明，通过施加压力，最佳掺杂超导材料在磁通钉扎或Jc方面的超导性能能够得到进一步改善。