Alduschenkov, A. V.Geraschenko, O. V.Kholmetskii, A. L.Lomonosov, V. A.Mahnach, L. V.Mashlan, M.Yarman, T.2024-05-252024-05-2520141557-19391557-194710.1007/s10948-014-2531-22-s2.0-84904465951https://doi.org/10.1007/s10948-014-2531-2https://hdl.handle.net/20.500.14517/737TUČEK, Jiří/0000-0003-2037-4950; Yarman, Tolga/0000-0003-3209-2264; Tucek, Jiri/0000-0003-1864-259XWe report the results of investigation of high-temperature superconductor (HTSC) LaFeO F(1-x) (x) As at x = 0.15. We applied the XRD method, the measurement of the hysteresis curve and resistivity, as well as the Mossbauer measurements at the temperature range 4.2-300 K. We show that in the given sample, owing to doping by fluorine, full suppression of antiferromagnetism is not accompanied by the rise of superconductivity. Instead, we observe a high-temperature (at T a parts per thousand currency sign 40 K) Kondo effect, which indicates a strong coupling of electron's spins with the magnetic moments of impurities. We also find a correlation between the revealed high-temperature Kondo effect and the appearance of a quadrupole splitting in the Mossbauer spectra below 40 K. The revealed effects can shed light on the mechanism of superconductivity in the iron-containing HTSC.eninfo:eu-repo/semantics/closedAccessIron-containing superconductorsMossbauer spectroscopyKondo effectArticle2