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arXiv · 1006.3471

Competition of local-moment ferromagnetism and superconductivity in Co-substituted EuFe2As2

M. Nicklas·M. Kumar·E. Lengyel·W. Schnelle·A. Leithe-Jasper
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Abstract

In contrast to SrFe2As2, where only the iron possesses a magnetic moment, in EuFe2As2 an additional large, local magnetic moment is carried by Eu2+. Like SrFe2As2, EuFe2As2 exhibits a spin-density wave transition at high temperatures, but in addition the magnetic moments of the Eu2+ order at around 20 K. The interplay of pressure-induced superconductivity and the Eu2+ order leads to a behavior which is reminiscent of re-entrant superconductivity as it was observed, for example, in the ternary Chevrel phases or in the rare-earth nickel borocarbides. Here, we study the delicate interplay of the ordering of the Eu2+ moments and superconductivity in EuFe1.9Co0.1As2, where application of external pressure makes it possible to sensitively tune the ratio of the magnetic (T_C) and the superconducting (T_{c,onset}) critical temperatures. We find that superconductivity disappears once T_C > T_{c,onset}.

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M. Nicklas, M. Kumar, E. Lengyel, W. Schnelle, A. Leithe-Jasper. 2010-06-17. Competition of local-moment ferromagnetism and superconductivity in Co-substituted EuFe2As2. https://doi.org/10.1088/1742-6596/273/1/012101

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