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arXiv · 1103.0098

Spin excitations in K$_{0.84}$Fe$_{1.99}$Se$_2$ superconductor as studied by Mössbauer spectroscopy

Zhiwei Li·Xiaoming Ma·Hua Pang·Fashen Li
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Abstract

Mössbauer spectroscopy was used to probe the site specific information of the $K_{0.84}Fe_{1.99}Se_2$ superconductor. Possibility of coexistence of superconductivity and magnetism is discussed. A spin excitation gap, $ΔE \approx$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 a simple model suggested in the literature, the temperature dependence of the HMF is well reproduced, suggesting that, below room temperature, the 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.

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Zhiwei Li, Xiaoming Ma, Hua Pang, Fashen Li. 2012-04-02. Spin excitations in K$_{0.84}$Fe$_{1.99}$Se$_2$ superconductor as studied by Mössbauer spectroscopy. https://doi.org/10.1088/1674-1056%2F21%2F4%2F047601

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