Tunable critical temperature for superconductivity in FeSe thin films by pulsed laser deposition

Zhongpei Feng; Jie Yuan; Ge He; Wei Hu; Zefeng Lin; Dong Li; Xingyu Jiang; Yulong Huang; Shunli Ni; Jun Li; Beiyi Zhu; Xiaoli Dong; Fang Zhou; Huabing Wang; Zhongxian Zhao; Kui Jin

doi:10.1038/s41598-018-22291-z

Tunable critical temperature for superconductivity in FeSe thin films by pulsed laser deposition

Sci Rep. 2018 Mar 6;8(1):4039. doi: 10.1038/s41598-018-22291-z.

Authors

Zhongpei Feng^{1

2}, Jie Yuan^{3

4}, Ge He^{1

2}, Wei Hu^{1

2}, Zefeng Lin^{1

2}, Dong Li^{1

2}, Xingyu Jiang^{1

2}, Yulong Huang^{1

2}, Shunli Ni^{1

2}, Jun Li⁵, Beiyi Zhu¹, Xiaoli Dong^{1

2}, Fang Zhou^{1

2}, Huabing Wang⁶, Zhongxian Zhao^{1

2

7}, Kui Jin^{8

9

10}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
² Key Laboratory of Vacuum Physics, School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. yuanjie@iphy.ac.cn.
⁴ Key Laboratory of Vacuum Physics, School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China. yuanjie@iphy.ac.cn.
⁵ Research Institute of Superconductor Electronics, Nanjing University, Nanjing, 210093, China. junli@nju.edu.cn.
⁶ Research Institute of Superconductor Electronics, Nanjing University, Nanjing, 210093, China.
⁷ Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
⁸ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. kuijin@iphy.ac.cn.
⁹ Key Laboratory of Vacuum Physics, School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China. kuijin@iphy.ac.cn.
¹⁰ Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China. kuijin@iphy.ac.cn.

Abstract

Stabilized FeSe thin films in ambient pressure with tunable superconducting critical temperature would be a promising candidate for superconducting electronic devices. By carefully controlling the depositions on twelve kinds of substrates using a pulsed laser deposition technique single crystalline FeSe thin films were fabricated. The high quality of the thin films was confirmed by X-ray diffraction with a full width at half maximum of 0.515° in the rocking curve and clear four-fold symmetry in φ-scan. The films have a maximum T _c ~ 15 K on the CaF₂ substrate and were stable in ambient conditions air for more than half a year. Slightly tuning the stoichiometry of the FeSe targets, the superconducting critical temperature becomes adjustable below 15 K with quite narrow transition width less than 2 K. These FeSe thin films deposited on different substrates are optimized respectively. The T_c of these optimized films show a relation with the out-of-plane (c-axis) lattice parameter of the FeSe films.