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

doi:10.1088/1361-6668/aae42d

paper

Single-crystal growth of iron-based superconductor La $_{0.34}$ Na $_{0.66}$ Fe $_{2}$ As $_{2}$

arXiv:1805.08923 · doi:10.1088/1361-6668/aae42d

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.

11 pages, 5 figures

Single-crystal growth of iron-based superconductor La0.34​Na0.66​Fe2​As2​

Abstract

Single-crystal growth of iron-based superconductor La $_{0.34}$ Na $_{0.66}$ Fe $_{2}$ As $_{2}$