New approaches to iron-based superconductors

2008年发现了一系列新的含有砷化铁、磷化物或硒化物层的高温超导体，在过去的两年里，主要的研究工作试图理解这一现象。新的超导体引起了人们的极大兴趣，因为它们在制造用于高场应用的超导磁体以及制造某些电信和电子设备的高级部件方面非常重要。新超导体的发现，特别是那些表现出非常规行为的超导体，不符合巴丁-库珀-施里弗模型，提供了在接近环境温度下超导的可能性，是蓝天研究的一个例子，未来可能会有重要的技术成果。这方面的研究表明，几种具有相似结构特征的化合物表现出超导电性，但基本测量发现了相当少量的此类化合物--那些最适合晶体生长的化合物。虽然大多数小组一直专注于现有的化合物，但在这一领域取得实质性进展的最直接途径是通过创新的材料发现，我们独特的战略包括尝试合成具有砷化铁或硒化铁的新型化合物，这些化合物可能具有比迄今发现的材料更好的性能。特别是，我们的重点是利用低温合成来获得在高温下热力学不稳定的化合物。这有望开启这些超导体研究的新篇章。合成将与实验室和国际设施中的物理性质测量并行进行，这对于了解这些化合物的超导电性和磁性如何与组成和晶体结构相关将是重要的。这些结果将被反馈到合成计划中。新化合物的样本将提供给社区其他成员，他们的专业知识是物理性质的专门测量。最终，这项研究可能会产生新的超导材料，这些材料中的组成、晶体结构和物理性质之间的相关性，并为这些材料为什么会超导提供基本的见解，可能为预测非传统超导现象的理论治疗铺平道路。

In 2008 a new series of high temperature superconductors containing iron arsenide, phosphide or selenide layers was discovered and in the last 2 years major research efforts have attempted to understand the phenomenon. New superconductors generate enormous interest as they are important in the manufacture of superconducting magnets for high field applications and in the manufacture of superior components for certain telecommunications and electronic devices. The discovery of new superconductors, particularly those which exhibit unconventional behaviour and do not conform to the Bardeen-Cooper-Schrieffer model, offers the possibility of superconductivity at temperatures approaching ambient and is an example of blue-skies research which may have an important technological payoff in the future. The research in this area has shown that several compounds with similar structural features exhibit superconductivity, but the fundamental measurements have probed a rather small number of these compounds - those which are most amenable to crystal growth. While most groups have been focused on existing compounds, the most direct route to substantial progress in this area is via innovative materials discovery and our unique strategy includes an attempt to synthesise new classes of compound with iron arsenide or iron selenide layers which may have superior properties to the materials discovered thus far. In particular our focus is on using low temperature synthesis to access compositions which are not thermodynamically stable at high temperatures. This is expected to open a new chapter in the study of these superconductors. The synthesis will be carried out in parallel with physical property measurements in the laboratory and at international facilities which will be important for understanding how the superconductivity and magnetism in these compounds is correlated with composition and crystal structure. These results will be fed back into the synthetic programme. Samples of the new compounds will be made available to other members of the community whose expertise is in specialised measurements of physical properties. Ultimately the research may yield new superconducting materials, correlations between composition, crystal structure and physical properties in these materials, and also offer fundamental insights into why these materials superconduct, possibly paving the way for predictive theoretical treatments of the phenomenon of unconventional superconductivity .