Alduschenkov, A. V.Geraschenko, O. V.Kholmetskii, A. L.Lomonosov, V. A.Mahnach, L. V.Mashlan, M.Yarman, T.2024-05-252024-05-2520151557-19391557-194710.1007/s10948-015-3088-42-s2.0-84938741509https://doi.org/10.1007/s10948-015-3088-4https://hdl.handle.net/20.500.14517/316Yarman, Tolga/0000-0003-3209-2264; TUČEK, Jiří/0000-0003-2037-4950; Tucek, Jiri/0000-0003-1864-259XThis study continues our investigation of high-temperature superconductors of LaFeO(1-x)F (x) As type initiated in our previous paper (J. Supercond. Nov. Magnetism 27, 1825, [1]), where the high-temperature Kondo effect had been observed in the sample with x = 0.15. We proceed with exploring the properties of the LaFeO (0.88) F As-0.12 sample, applying the X-ray diffraction (XRD) method, resistivity measurement, and the magnetic and Mossbauer measurements at the temperature range of 4.2-300 K. We observe the emergence of high-temperature Kondo effect at the temperatures between 30 and 50 K. At the same time, as opposed to the case x=0.15, we reveal the transformation of the high-temperature Kondo effect to the high-temperature superconductivity at the temperature near 25 K. The Mossbauer spectra of the sample obtained at different temperatures represent a single line, lying near zero relative velocity and do not exhibit any visible alterations. Concurrently, the application of an external magnetic field of 5 T to the sample at 5 K induces the emergence of a hyperfine magnetic splitting with the effective magnetic field on resonant nuclei H (ef) = 45.5 kOe. We suppose that the appearance of a magnetic ordering in the sample occurs due to the alignment of magnetic moments of impurities that confirms our hypothesis about a strong coupling of electron's spins with the magnetic moments of impurities in iron-containing superconductors.eninfo:eu-repo/semantics/closedAccessHigh-temperature superconductivityIron-containing superconductorsMossbauer spectroscopyArticleQ3Q328926572662WOS:0003592454000060