Superconducting (Li,Fe)OHFeSe Film of High Quality and High Critical Parameters
Yulong Huang1,2†, Zhongpei Feng1,2†, Shunli Ni1,2†, Jun Li4, Wei Hu1,2, Shaobo Liu1,2, Yiyuan Mao1,2, Huaxue Zhou1, Fang Zhou1,2, Kui Jin1,2,3**, Huabing Wang4, Jie Yuan1,3**, Xiaoli Dong1,2,3**, Zhongxian Zhao1,2,3**
1Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 2University of Chinese Academy of Sciences, Beijing 100049 3Key Laboratory for Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049 4Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093
Abstract：A superconducting film of (Li$_{1-x}$Fe$_{x})$OHFeSe is reported for the first time. The thin film exhibits a small in-plane crystal mosaic of 0.22$^{\circ}$, in terms of the full width at half maximum of the x-ray rocking curve, and an excellent out-of-plane orientation by x-ray $\varphi $-scan. Its bulk superconducting transition temperature $T_{\rm c}$ of 42.4 K is characterized by both zero electrical resistance and diamagnetization measurements. The upper critical field $H_{\rm c2}$ is estimated to be 79.5 T and 443 T for the magnetic field perpendicular and parallel to the $ab$ plane, respectively. Moreover, a large critical current density $J_{\rm c}$ of a value over 0.5 MA/cm$^{2}$ is achieved at $\sim $20 K. Such a (Li$_{1-x}$Fe$_{x})$OHFeSe film is therefore not only important to the fundamental research for understanding the high-$T_{\rm c}$ mechanism, but also promising in the field of high-$T_{\rm c}$ superconductivity application, especially in high-performance electronic devices and large scientific facilities such as superconducting accelerator.
2017, Vol. 34 
