The team of Professor Chongde Cao of our School of Science worked with a team of Professor Pengcheng Dai of the University of Rice in the United States, as well as with their counterparts at the Maple Solid Institute of Germany, the American Bureau of Standards, the Oak Ridge National Laboratory and Renmin University of China, to study the relationship between the structure, magnetism and superconductivity of NI doped NeFeAs Iron-based superconductors Strange distortion phenomena have been found in high temperature superconductors, and it is found that the fluctuation of the column is helpful to the formation of superconductivity. The results of the study, entitled "Local orthorhombic lattice distortions in the paramagnetic tetragonal phase of superconducting NaFe1−xNixAs", were held on 7/8/2018. Published online on August 7thin Nature Communications, Professor Chongde Cao and Professor Pengcheng Dai as co-authors of the article. Paper Link: https://www.nature.com/articles/s41467-018-05529-2. This is the first time they have found Mott insulators near Iron-based superconductivity (Nature Communications, 2016, 7, 13879; https://www.nature.com/articles/ncomms13879) After another important research progress.
Superconducting material is a material that has the properties of zero resistance and rejection of magnetic lines at a certain low temperature. When the superconducting material is in the superconducting state, the resistance is zero and the power can be transmitted without loss, which means the rapid transfer of electrical energy and information. As a special category of important functional materials, superconducting materials have been widely used in superconducting strong magnets, high-energy particle accelerators, magnetic levitation transport (such as Maglev trains), controlled thermonuclear reaction, communication cables and antennas, energy storage devices, important precision measuring instruments, medical devices, radiation detectors, microwave generators and so on. In addition, superconducting materials are also the key materials for quantum communication. So far, the critical superconducting temperature of the superconducting material has been found to be much lower than zero, and finding the room temperature superconducting material is one of the human dreams, and the premise of realizing this dream is to understand the mechanism of superconducting production. However, the superconducting mechanism is unclear.
Iron-based superconductivity is a special new type of superconducting material discovered in the 2008, the previous theory that superconductivity and ferromagnetic can not coexist, so before that ferromagnetic materials were considered impossible to produce superconductivity. Therefore, the discovery of Iron-based superconductivity has great significance, and the mechanism of Iron-based superconductivity was a major research problem in the field of physics and materials science in the past ten years, but the problem has not been solved so far.
The fluctuation of electron to column becomes very large near the quantum critical point, which is bound by the local crystal defects and impurities, and manifests itself in the local lattice distortion measured by the experimental work. The most interesting and important thing is that when this happens, superconductivity is strongest, suggesting that these fluctuations in the column contribute to the formation of superconductivity. This finding is of great significance not only to improve the superconducting critical temperature of iron phosphate, but also to provide a theoretical basis for better design of materials with novel and predictable properties.
The study was developed by the National Natural Science Foundation of the China (51471135), The National Key Research and Development Program of China (2016YFB1100101), the Key International Cooperation Project for Key Research and Development Program of Shaanxi (2017KWZD-07) and the Shenzhen Science and Technology Innovation Program Project ( The support of JCYJ20170815162201821).
In recent years, the Chongde Cao’ team has been published academic achievements in Nature Communications, Physical Review Letters, Scientific Reports, Physical review B, Crystal Growth & Design and other world-class journals.
Fig. 1. Super large NI doped nafeas monocrystals.