摘要
We report a hydrothermal route to remove interstitial excess Fe in non-superconducting iron chalcogenide Fe_(1+δ)Se_(1-x)Te_(x) single crystals.The extra-Fe-free(δ~0)FeSe_(0.2)Te_(0.8) single crystal thus obtained shows bulk superconductivity at T_c~13.8 K,which is about 2 K higher than the FeSe_(0.2)Te_(0.8) sample obtained by usual postannealing process.The upper critical fieldμ_0H_(c2) is estimated to be~42.5 T,similar to the annealed FeSe_(0.2)Te_(0.8).It is surprising to find that the hydrothermal FeSe_(0.2)Te_(0.8)exhibits a remarkably small isothermal magnetization hysteresis loop at T=3 K.This yields an extremely low critical current density J_(c)~1.1×10^(2)A·cm^(-2)(over 100times smaller than the annealed FeSe_(0.2)Te_(0.8)) and indicates more free vortices in the hydrothermal FeSe_(0.2)Te_(0.8).
作者
马晟
闫珊珊
刘家利
王怡哲
张宇航
赵振
鲁邹有为
李栋
刘樾
卢佶虎
张华
杨海涛
周放
李子安
董晓莉
赵忠贤
Sheng Ma;Shanshan Yan;Jiali Liu;Yizhe Wang;Yuhang Zhang;Zhen Zhao;Zouyouwei Lu;Dong Li;Yue Liu;Jihu Lu;Hua Zhang;Haitao Yang;Fang Zhou;Zian Li;Xiaoli Dong;Zhongxian Zhao(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physical Science and Technology,Guangxi University,Nanning 530004,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China)
基金
the National Natural Science Foundation of China(Grant Nos.12061131005,11974019,11834016,and 11888101)
the National Key Research and Development Program of China(Grant Nos.2022YFA1403900)
the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB33010200 and XDB25000000)
the Chinese Academy of Sciences through the Youth Innovation Promotion Association(Grant No.2022YSBR-048)。
