新型铁基超导材料的制备和性能

Development of iron-based superconducting materials for applications

铁基超导体是目前超导材料研究领域最受关注的研究方向之一,激发了凝聚态物理学家和材料学家广泛的兴趣.与近20多年来被广泛研究的铜氧化物超导体相比,铁基超导体具有非常高的上临界场、较低的各向异性,同时具有较高的临界电流密度,展现了良好的潜在应用价值.本文简述了新型铁基超导材料的发现、发展历程,对比了目前发现的几种铁基超导体的晶体结构,并详细分析了1111,122,11等几种铁基超导线带材和薄膜制备工艺的优化过程.同时,针对当前铁基超导体的研究现状,探讨了提高铁基超导材料临界电流密度的途径.

The discovery of superconductivity in iron pnictides has generated a great deal of research interest, not only in basic physics, but also in the field of applied superconductivity. It has been confirmed that the pnictides have peculiar physical properties including an unconventional pairing mechanism. This brings an opportunity to discover new kind of superconductor with high transition temperature. On the other hand, compare to the cuprate, the iron-based superconductors have a rather high upper critical field （He2） and low anisotropy. These properties are very attractive for practical application. An overview of the development of iron-based supercoaductors is presented in this article. The crystal structure of various iron-based superconductors is presented. At the same time, the fabrication techniques of iron-based tapes and films for ＂1111＂, ＂122＂, ＂11＂ type of pnictide are reviewed. Some promising features such as a high critical current density in tapes and thin films under high magnetic fields have been clarified. Finally, we summarize and compare the features and properties of the pnictide materials with other classical cuprate and MgB~ superconductors.