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arXiv · 1805.08923

Single-crystal growth of iron-based superconductor La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$

Yanhong Gu·Jia-Ou Wang·Xiaoyan Ma·Huiqian Luo·Youguo Shi·Shiliang Li
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Abstract

We report single-crystal growth of La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$ iron-based superconductor with the size of several millimeters. The samples were accidentally obtained in trying to grow LaFeAsO$_{1-y}$F$_y$ ( $y \geq$ 0.8 ) single crystals with NaAs and NaF flux. The sample shows both antiferromagnetic and structural transitions at 106 K. The superconducting transition temperature is about 27 K with the superconducting anisotropy of about 1.9. These values and the temperature dependence of the Hall coefficient suggest that La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$ belongs to hole-doped "122" families of iron pnictides with the doping level slightly lower than optimal doping. Compared with previous reports on the polycrystalline samples, our results suggest that either $T_c$ of the this system can be further increased, or the superconducting dome may not be well formed in this system. In either case, the La$_{0.5-x}$Na$_{0.5+x}$Fe$_2$As$_2$ system provides a new platform to study the antiferromagnetic and superconducting properties of iron-based superconductors.

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Yanhong Gu, Jia-Ou Wang, Xiaoyan Ma, Huiqian Luo, Youguo Shi, Shiliang Li. 2018-05-23. Single-crystal growth of iron-based superconductor La$_{0.34}$Na$_{0.66}$Fe$_2$As$_2$. https://doi.org/10.1088/1361-6668%2Faae42d

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