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Information × Registration Number 0219U102067, 0119U102958 , R & D reports Title Microwave conductivity of iron-based pnictides and chalcogenides in superconducting and normal states popup.stage_title Head Cherpak Mykola T., Доктор фізико-математичних наук Registration Date 17-12-2019 Organization O. Ya. Usikov Institute for Radiophysics and Electronics NAS of Ukraine popup.description2 Object of study - the processes of interaction of microwave (MW) field with unusual superconductors in superconducting and normal states. The purpose of the work - to obtain the temperature dependence of the complex conductivity of superconductors with Fe ions in the MW range. This is important to understanding the nature of unusual superconductivity. Research methods - experimental measurement of MW surface impedance superconductors of resonator methods followed by the finding complex conductivity, numerical modeling of quasioptic dielectric resonators (QDR) with samples of superconductors, processing measurement results using a software product created in O.Ia. Usikov NAS of Ukraine. A technique for measuring the impedance of superconductors in the N-state based on sapphire QDR has been developed. It is shown that, depending on the size of the superconducting specimens, QDRs in the form of a cylindrical disk, a cut cone, or an aspherical disk may be used In order to increase the reliability of the experimental results, a two-frequency approach is proposed. The approach is realized on the example of a single crystal pnictide Ba (Fe1-xCox)2As2 in the Ka- and X-bands. For the first time, the MW surface impedance of a single crystal of a new superconducting chalcogenide (Li1-xFex) OHFeSe (x ≈ 0.2) was obtained. It is shown that the behavior of a superconductor corresponds to the presence of a completely open energy gap in the spectrum of the electronic system. In addition, the inequality of resistance and reactance in the N-state, which in this case can be caused by a magnetic system in the composition of a superconductor, is found. The further research is needed here. Product Description popup.authors Barannik Alexander A. Vovnyuk Maksym V. Gubin Alexey I. Korolev Olexy M. Lavrinovich Alexander A. Protsenko Iryna O. Cherpak Mykola T. popup.nrat_date 2020-04-02 Close