SrTiO3(100)衬底上原子级厚度LiFeAs薄膜的生长和表征
Growth and charaterization of atomic thick LiFeAs on SrTiO3(100) substrate
通过分子束外延方法，我们在Nb掺杂的SrTiO3(100)衬底上，制备出了原子级厚度的LiFeAs薄膜，并利用低温扫描隧道显微镜表征其表面形貌和电子结构。在330~345℃衬底温度下生长的单层和双层LiFeAs薄膜，其扫描隧道谱在费米能级附近表现出能隙的特征（4.7 K）。而将薄膜退火至450~490℃后，无论单层或双层LiFeAs薄膜的扫描隧道谱均未表现出能隙。因此，单层或双层的LiFeAs薄膜不能像FeSe薄膜一样通过长时间高温退火实现超导，其原因可能有电子转移程度不同、成膜质量不同等。
tomic-thick LiFeAs thin films were grown on Nb doped SrTiO3(100) substrate through molecular beam epitaxy. Its surface topology and electronic structure were characterized by low temperature scanning tunneling microscope. When the growth temperature is 330~345℃, gap features appear on the scanning tunneling spectra of the LiFeAs films with the thickness of one or two quintuple-layers (QL), acquired at 4.7 K. However, no superconducting gap is observed after they are annealed at the temperature of 450~490℃. Therefore, in the contrast to the single-layer FeSe film, superconductivity cannot be realized through high-temperature and long-time annealing in 1 or 2 QL LiFeAs films. This is probably because of the differences in electron transfer or film quality.
常凯、黄万通、薛其坤、季帅华、赵琨、陈曦、林海城
物理学材料科学晶体学
分子束外延铁基超导体LiFeAs
molecule beam epitaxyiron-based superconductorLiFeAs
常凯,黄万通,薛其坤,季帅华,赵琨,陈曦,林海城.SrTiO3(100)衬底上原子级厚度LiFeAs薄膜的生长和表征[EB/OL].(2017-05-31)[2025-08-02].http://www.paper.edu.cn/releasepaper/content/201705-1446.点此复制
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