Doping Effects of Co, Ni, and Cu in FeTe0.65Se0.35 Single Crystals
V.L. Bezusyy, D.J. Gawryluk, M. Berkowski and M.Z. Cieplak
Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
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The resistivity, magnetoresistance, and magnetic susceptibility are measured in single crystals of FeTe0.65Se0.35 with Cu, Ni, and Co substitutions for Fe. The crystals are grown by Bridgman's method. The resistivity measurements show that superconductivity disappears with the rate which correlates with the nominal valence of the impurity. From magnetoresistance we evaluate doping effect on the basic superconducting parameters, such as upper critical field and coherence length. We find indications that doping leads to two component superconducting behavior, possibly because of local charge depression around impurities.
DOI: 10.12693/APhysPolA.121.816
PACS numbers: 74.25.F-, 74.25.Op, 74.62.Dh, 74.70.Xa