中国物理B ›› 2013, Vol. 22 ›› Issue (8): 86801-086801.doi: 10.1088/1674-1056/22/8/086801

所属专题: TOPICAL REVIEW — Iron-based high temperature superconductors

• TOPICAL REVIEW—Iron-based high temperature superconductors • 上一篇    下一篇

Molecular beam epitaxy and superconductivity of stoichiometric FeSe and KxFe2-ySe2 crystalline films

王立莉a, 马旭村a, 陈曦b, 薛其坤b   

  1. a Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    b State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
  • 收稿日期:2013-05-03 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project supported by the National Natural Science Foundation of China and the National Basic Research Program of China.

Molecular beam epitaxy and superconductivity of stoichiometric FeSe and KxFe2-ySe2 crystalline films

Wang Li-Li (王立莉)a, Ma Xu-Cun (马旭村)a, Chen Xi (陈曦)b, Xue Qi-Kun (薛其坤)b   

  1. a Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    b State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
  • Received:2013-05-03 Online:2013-06-27 Published:2013-06-27
  • Contact: Xue Qi-Kun E-mail:qkxue@mail.tsinghua.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China and the National Basic Research Program of China.

摘要: Our recent progress in the fabrication of FeSe and KxFe2-ySe2 ultra thin films and the understanding of their superconductivity properties is reviewed. The growth of high-quality FeSe and KxFe2-ySe2 films is achieved in a well controlled manner by molecular beam epitaxy. The high-quality stoichiometric and superconducting crystalline thin films allow us to investigate the intrinsic superconductivity properties and the interplay between the superconductivity and the film thickness, the local structure, the substrate, and magnetism. In situ low-temperature scanning tunneling spectra reveal the nodes and the twofold symmetry in FeSe, high-temperature superconductivity at the FeSe/SrTiO3 interface, phase separation and magnetic order in KxFe2-ySe2, and the suppression of superconductivity by twin boundaries and Fe vacancies. Our findings not only provide fundamental information for understanding the mechanism of unconventional superconductivity, but also demonstrate a powerful way of engineering superconductors and raising the transition temperature.

关键词: superconducting films, Fe-based superconductors, molecular beam epitaxy, scanning tunneling microscopy

Abstract: Our recent progress in the fabrication of FeSe and KxFe2-ySe2 ultra thin films and the understanding of their superconductivity properties is reviewed. The growth of high-quality FeSe and KxFe2-ySe2 films is achieved in a well controlled manner by molecular beam epitaxy. The high-quality stoichiometric and superconducting crystalline thin films allow us to investigate the intrinsic superconductivity properties and the interplay between the superconductivity and the film thickness, the local structure, the substrate, and magnetism. In situ low-temperature scanning tunneling spectra reveal the nodes and the twofold symmetry in FeSe, high-temperature superconductivity at the FeSe/SrTiO3 interface, phase separation and magnetic order in KxFe2-ySe2, and the suppression of superconductivity by twin boundaries and Fe vacancies. Our findings not only provide fundamental information for understanding the mechanism of unconventional superconductivity, but also demonstrate a powerful way of engineering superconductors and raising the transition temperature.

Key words: superconducting films, Fe-based superconductors, molecular beam epitaxy, scanning tunneling microscopy

中图分类号:  (Scanning tunneling microscopy (including chemistry induced with STM))

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