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arXiv · 0807.0823

Superconductivity in Co-doped LaFeAsO

Athena S. Sefat·Ashfia Huq·Michael A. McGuire·Rongying Jin·Brian C. Sales·David Mandrus
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Abstract

Here we report the synthesis and basic characterization of LaFe1-xCoxAsO for several values of x. The parent phase LaFeAsO orders antiferromagnetically (TN ~ 145 K). Replacing Fe with Co is expected to both electron dope the system and introduce disorder in the FeAs layer. For x = 0.05 antiferromagnetic order is destroyed and superconductivity is observed at Tconset = 11.2 K. For x = 0.11 superconductivity is observed at Tc(onset) = 14.3 K, and for x = 0.15 Tc = 6.0 K. Superconductivity is not observed for x = 0.2 and 0.5, but for x = 1, the material appears to be ferromagnetic (Tc ~ 56 K) as judged by magnetization measurements. We conclude that Co is an effective dopant to induce superconductivity. Somewhat surprisingly, the system appears to tolerate considerable disorder in the FeAs planes.

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Athena S. Sefat, Ashfia Huq, Michael A. McGuire, Rongying Jin, Brian C. Sales, David Mandrus. 2008-07-04. Superconductivity in Co-doped LaFeAsO. https://doi.org/10.1103/physrevb.78.104505

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