摘要
Spatially uniform high-temperature superconducting films are highly desirable for exploring novel properties and popularizing applications.To improve the uniformity,we fabricate monolayer FeSexTe1−x(0<x≤1)films on SrTiO3(001)by topotactic reaction of monolayer FeTe films with selenium.Using in situ low-temperature scanning tunneling microscopy/spectroscopy,we demonstrate atomic-level uniformity of element distribution and well-defined superconducting gaps of~15 meV in FeSexTe1−x films.In particular,the monolayer FeSe films exhibit fewer line defects and higher superfluid density as evidenced by sharper coherence peaks than those prepared by the co-evaporation method.Our results provide a promising way to optimize sample quality and lay a foundation for studying new physics and drawing reliable conclusions.
基金
This work was supported by the National Natural Science Foundation of China(Nos.12074210,51788104 and 11790311)
the National Basic Research Program of China(Nos.2017YFA0303303)
the Basic and Applied Basic Research Major Programme of Guangdong Province,China(No.2021B0301030003)
Jihua Laboratory(No.X210141TL210).
