Dresden 2017 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 53: Poster Session: Superconductivity 1
TT 53.16: Poster
Mittwoch, 22. März 2017, 15:00–19:00, P2-OG2
Doping effect of Mn impurities on the physical properties of optimally electron doped Sr(Fe0.86Co0.14)2As2 — •Luminita Harnagea, Giri Mani, and Surjeet Singh — Indian Institute of Science Education and Research, Pune - 411008, India.
Using transport and magnetization measurements we studied the effect of Mn doping in optimally electron doped Sr(Fe0.86Co0.14)2As2 single crystal. The as - grown Sr(Fe0.86Co0.14)2As2 single crystal exhibits a superconducting transition temperature (Tc) of around 15 K. Doping with Mn at the Fe site in Sr(Fe0.86Co0.14)2As2 leads to a gradual suppression of the transition temperature with an initial rate of about ΔTc 5 K per Mn percentage. The residual resistivity of the doped samples increases with increasing Mn concentration. The low-temperature magnetic susceptibility of the Mn-doped samples exhibits a Curie tail, which gets progressively enhanced with increasing Mn - concentration, suggesting that the Mn - ions carry a localized magnetic moment consistent with S = 1/2 local moment. The paramagnetic Mn moments act as Cooper pair-breakers resulting in a gradual suppression of Tc, analogous to Ba(Fe1−x−yCoxMny)2As2 series of compounds . These results are, however, in stark contrast with the case of Mn doped LaFeAsO0.89F0.11, where a Mn concentration as small as 0.2 %, suppresses the superconductivity completely . These differences are rather surprising and their more detailed understanding might throw light on the nature of superconducting state in iron pnictides.
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