中国物理B ›› 2012, Vol. 21 ›› Issue (4): 47601-047601.doi: 10.1088/1674-1056/21/4/047601

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李志伟,马小明,庞华,李发伸   

  • 收稿日期:2011-12-14 修回日期:2012-01-12 出版日期:2012-02-29 发布日期:2012-02-29
  • 通讯作者: 庞华,hpang@lzu.edu.cn E-mail:hpang@lzu.edu.cn

Spin excitations in a K0.84Fe1.99Se2 superconductor as studied by Mössbauer spectroscopy

Li Zhi-Wei(李志伟), Ma Xiao-Ming(马小明), Pang Hua(庞华), and Li Fa-Shen(李发伸)   

  1. Institute of Applied Magnetics, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • Received:2011-12-14 Revised:2012-01-12 Online:2012-02-29 Published:2012-02-29
  • Contact: Pang Hua,hpang@lzu.edu.cn E-mail:hpang@lzu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 10975066).

Abstract: Mössbauer spectroscopy was used to probe the site-specific information of a K0.84Fe1.99Se2 superconductor. A spin excitation gap, ΔE ≈5.5 meV, is observed by analyzing the temperature dependence of the hyperfine magnetic field (HMF) at the iron site within the spin wave theory. Using the simple model suggested in the literature, the temperature dependence of the HMF is well reproduced, suggesting that, below room temperature, the alkali metal intercalated iron-selenide superconductors can be regarded as ferromagnetically coupled spin blocks that interact with each other antiferromagnetically to form the observed checkerboard-like magnetic structure.

Key words: Mössbauer spectroscopy, iron-selenide, superconductivity

中图分类号:  (M?ssbauer effect; other γ-ray spectroscopy)

  • 76.80.+y
74.10.+v (Occurrence, potential candidates)