2022年11月21日
Spin fluctuations in the 112-type iron-based superconductor Ca0.82La0.18Fe0.96Ni0.04As2
Journal of Physics: Condensed Matter
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- 巻
- 34
- 号
- 47
- 開始ページ
- 474001
- 終了ページ
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1088/1361-648x/ac9441
- 出版者・発行元
- IOP Publishing
Abstract
We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) Ca0.82La0.18Fe0.96Ni0.04As2 (CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space group $I4/mmm$) at room temperature and an in-plane stripe-type antiferromagnetic (AF) order at low temperature, the 112 system has a noncentrosymmetric structure (space group $P2_{1}$) with additional zigzag arsenic chains between Ca/La layers and a magnetic ground state with similar wavevector $\mathbf{Q}_{\mathrm{AF } }$ but different orientations of ordered moments in the parent compounds. Our INS study clearly reveals that the in-plane dispersions and the bandwidth of spin excitations in the superconducting CaLa-112 closely resemble to those in 122 systems. While the total fluctuating moments $\langle m^2 \rangle\approx 4.6 \pm 0.2\,\mu_\mathrm{B}^2$/Fe are larger than 122 system, the dynamic correlation lengths are similar (ξ ≈ 10 Å). These results suggest that superconductivity in iron arsenides may have a common magnetic origin under similar magnetic exchange couplings with a dual nature from local moments and itinerant electrons, despite their different magnetic patterns and lattice symmetries.
We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) Ca0.82La0.18Fe0.96Ni0.04As2 (CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space group $I4/mmm$) at room temperature and an in-plane stripe-type antiferromagnetic (AF) order at low temperature, the 112 system has a noncentrosymmetric structure (space group $P2_{1}$) with additional zigzag arsenic chains between Ca/La layers and a magnetic ground state with similar wavevector $\mathbf{Q}_{\mathrm{AF } }$ but different orientations of ordered moments in the parent compounds. Our INS study clearly reveals that the in-plane dispersions and the bandwidth of spin excitations in the superconducting CaLa-112 closely resemble to those in 122 systems. While the total fluctuating moments $\langle m^2 \rangle\approx 4.6 \pm 0.2\,\mu_\mathrm{B}^2$/Fe are larger than 122 system, the dynamic correlation lengths are similar (ξ ≈ 10 Å). These results suggest that superconductivity in iron arsenides may have a common magnetic origin under similar magnetic exchange couplings with a dual nature from local moments and itinerant electrons, despite their different magnetic patterns and lattice symmetries.
- リンク情報
- ID情報
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- DOI : 10.1088/1361-648x/ac9441
- ISSN : 0953-8984
- eISSN : 1361-648X