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arXiv · 1101.3159

The upper critical field and its anisotropy in LiFeAs

J. L. Zhang·L. Jiao·F. F. Balakirev·X. C. Wang·C. Q. Jin·H. Q. Yuan
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Abstract

The upper critical field $μ_0H_{c2}(T_c)$ of LiFeAs single crystals has been determined by measuring the electrical resistivity using the facilities of pulsed magnetic field at Los Alamos. We found that $μ_0H_{c2}(T_c)$ of LiFeAs shows a moderate anisotropy among the layered iron-based superconductors; its anisotropic parameter $γ$ monotonically decreases with decreasing temperature and approaches $γ\simeq 1.5$ as $T\rightarrow 0$. The upper critical field reaches 15T ($H\parallel c$) and 24.2T ($H\parallel ab$) at $T=$1.4K, which value is much smaller than other iron-based high $T_c$ superconductors. The temperature dependence of $μ_0H_{c2}(T_c)$ can be described by the Werthamer-Helfand-Hohenberg (WHH) method, showing orbitally and (likely) spin-paramagnetically limited upper critical field for $H\parallel c$ and $H\parallel ab$, respectively.

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J. L. Zhang, L. Jiao, F. F. Balakirev, X. C. Wang, C. Q. Jin, H. Q. Yuan. 2011-01-17. The upper critical field and its anisotropy in LiFeAs. https://doi.org/10.1103/physrevb.83.174506

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