Recently, Liu Dayong, a research associate of the Solid Physics Institute of the Chinese Academy of Sciences, and Zou Liangjian, a researcher, collaborated with Sun Yan, a professor at the National Synchrotron Radiation Laboratory of the University of Science and Technology of China, in the new intercalated iron-selenium superconducting material (Li1-xFex) OHFeSe. New advances in magnetic research have led to the existence of magnetism in local and paradoxical coexistence in this type of system, and proposed that intercalation magnetism can be used as a new mechanism to regulate spin-fluctuations associated with superconductivity in superconducting layers. The relevant results were published in the new journal of physics (19, 023028 (2017)) with the title Coexistence of localized and itinerant magnetism in intercalated iron-selenide (Li,Fe)OHFeSe. So far, iron-based superconducting materials have been mainly found in iron-phosphorus and iron-chalcogen compounds. The latter iron-selenium superconducting materials have attracted much attention due to their high superconducting transition temperatures. Although the superconducting transition temperature of bulk FeSe is only 8K, the superconducting transition temperature can be greatly improved by controlling its lattice structure. For example, when bulk FeSe is pressurized, the superconducting transition temperature can reach 37K, and the intercalated iron selenium material K1-xFe2-ySe2 reaches 30K. In particular, the monolayer FeSe (Fe/STO) grown on the SrTiO3 substrate can reach 65K. Superconducting transition temperatures of K up to 110 K. At present, theoretical research generally believes that the superconducting mechanism of iron-based superconducting materials is mainly related to the nesting of adjacent antiferromagnetic and fermionic hole/electron pockets of superconductors. Recently discovered a new type of intercalated iron-selenium superconductor material (Li1-xFex) OHFeSe, the superconducting transition temperature Tc up to 40 K, not only does not appear in the crystal structure similar to the intercalated iron selenium material K1-xFe2-ySe2 Fe vacancy , And there is a novel Fermi surface topological structure with hole-type pockets missing on the electronic structure. Therefore, the new intercalated iron-selenium superconductor (Li1-xFex) OHFeSe has become an important research object of iron-selenium superconducting materials. Further studies on it may clarify some of the key controversies in the research of iron-based superconducting materials. In order to study the properties of two different types of Fe in (Li1-xFex) OH layer and FeSe layer, the researchers studied and analyzed the ideal system LiOHFeSe and the actual material (Li0.8Fe0.2) OHFeSe using a combination of computational and theoretical models. Electronic structure and magnetic properties, found (Li1-xFex) OH layer Fe ions have +2 valence state, (Li0.8Fe0.2) OH intercalation is equivalent to the FeSe layer to provide electrons, with FeSe / STO very close to Electronic structure. The ground state of the intercalation layer is anti-ferromagnetic (Figure 1), which is local magnetic; while the FeSe layer is a striped anti-ferromagnetic metal (Figure 1); the ferromagnetic coupling between the layers (Li0.8Fe0.2) The magnetic structure of OHFeSe material is shown in Fig. 2. Therefore, the magnetic intercalation layer (Li1-xFex) OH not only acts as a space barrier layer, but also can regulate spin-fluctuation related to superconductor pairing in the FeSe layer through interlayer coupling. In addition, in order to study the magnetic interaction between spins of the material Fe, the researchers also constructed the J1-J2-J3-J'1-J'2-Jc Heisenberg model, and given the magnetic coupling constants, which can be used later Neutron scattering experiments and spin waves and other related experimental and theoretical work provide physical parameters. The above research results have been funded by National Natural Science Foundation projects and key projects. Brass Check Valves,1/2 Brass Check Valves,3/4 Brass Check Valves,Domestic Brass Check Valves AS-SUR INDUSTRIAL VALVE CO., LTD. , https://www.assur-valve.com