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arXiv · 1011.1334

Determination of the Upper Critical Field of a Single Crystal LiFeAs: The Magnetic Torque Study up to 35 Tesla

N. Kurita·K. Kitagawa·K. Matsubayashi·A. Kismarahardja·E. S. Choi·J. S. Brooks·Y. Uwatoko·S. Uji·T. Terashima
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Abstract

We report on the upper critical field B_c2 of a superconducting LiFeAs single crystal with T_c~16 K, determined from magnetic torque measurements in dc-magnetic fields up to 35 T and at temperatures down to 0.3 K. B_c2 at 0.3 K is obtained to be 26.4 T and 15.5 T for the applied field B_a||ab and B_a||c, respectively. The anisotropy parameter $Γ$=$B_c2^ab / B_c2^c$ is ~ 3 at T_c and decreases to 1.7 as $T \rightarrow 0$, showing rather isotropic superconductivity. While B_c2 is orbitally-limited for B_a||c, the spin-paramagnetic effect is evident in the temperature dependence of B_c2 for B_a||ab

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N. Kurita, K. Kitagawa, K. Matsubayashi, A. Kismarahardja, E. S. Choi, J. S. Brooks, Y. Uwatoko, S. Uji, T. Terashima. 2010-11-25. Determination of the Upper Critical Field of a Single Crystal LiFeAs: The Magnetic Torque Study up to 35 Tesla. https://doi.org/10.1143/jpsj.80.013706

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