Two-dimensional Cs-vacancy superstructure in iron-based superconductor $C{s}_{0.8}F{e}_{1.6}S{e}_2$

Abstract

Single crystal neutron diffraction is combined with synchrotron x-ray scattering to identify the different superlattice phases present in $C{s}_{0.8}F{e}_{1.6}S{e}_2$. A combination of single crystal refinements and first principles modelling are used to provide structural solutions for the $\sqrt{5}\times \sqrt{5}$ and $\sqrt{2}\times \sqrt{2}$ superlattice phases. The $\sqrt{5}\times \sqrt{5}$ superlattice structure is predominantly composed of ordered Fe vacancies and Fe distortions, whereas the $\sqrt{2}\times \sqrt{2}$ superlattice is composed of ordered Cs vacancies. The Cs vacancies only order within the plane, causing Bragg rods in reciprocal space. By mapping x-ray diffraction measurements with narrow spatial resolution over the surface of the sample, the structural domain pattern was determined, consistent with the notion of a majority antiferromagnetic $\sqrt{5}\times \sqrt{5}$ phase and a superconducting $\sqrt{2}\times \sqrt{2}$ phase.

REVTex 4.1, 7 pages, 5 figures

References in corpus (23)

• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Superconductivity in Iron Compounds
• Fe-based high temperature superconductivity with Tc=31K bordering an insulating antiferromagnet in (Tl,K)FexSe2 Crystals
• A Novel Large Moment Antiferromagnetic Order in K0.8Fe1.6Se2 Superconductor
• Superconductivity at 32 K in single crystal Rb${}_{0.78}$Fe${}_2$Se${}_{1.78}$}
• Synthesis and crystal growth of Cs0.8(FeSe0.98)2: a new iron-based superconductor with Tc=27K
• Phase Separation and Magnetic Order in K-doped Iron Selenide Superconductor
• Magnetism in Fe-based superconductors
• Nanoscale phase separation in the iron chalcogenide superconductor K0.8Fe1.6Se2 as seen via scanning nanofocused x-ray diffraction
• Microstructure and Fe-vacancy ordering in the KFexSe2 superconducting system
• On the Structure of Vacancy Ordered Superconducting Alkali Metal Iron Selenide
• Intrinsic phase separation in superconducting K0.8Fe1.6Se2 (Tc= 31.8 K) single crystals
• NMR Study in the Iron-Selenide Rb0.74Fe1.6Se2: Determination of the Superconducting Phase as Iron Vacancy-Free Rb0.3Fe2Se2
• Soft chemical control of superconductivity in lithium iron selenide hydroxides Li1-xFex(OH)Fe1-ySe
• Iron vacancy superstructure and possible room temperature antiferromagnetic order in superconducting Cs_{y}Fe_{2-x}Se_2
• Neutron-Diffraction Measurements of an Antiferromagnetic Semiconducting Phase in the Vicinity of the High-Temperature Superconducting State of K${}_x$Fe${}_{2-y}$Se${}_2$
• Antiferromagnetic order and superlattice structure in nonsuperconducting and superconducting RbyFe(1.6+x)Se2
• Microstructural analysis of phase separation in iron chalcogenide superconductors
• Imaging the coexistence of superconductivity and a charge density modulation in K0.73Fe1.67Se2 superconductor
• Intrinsic crystal phase separation in antiferromagnetic superconductor RbyFe2-xSe2: a diffraction study
• Spin-wave excitations and superconducting resonant mode in Cs(x)Fe(2-y)Se2
• Block Antiferromagnetism and Checkerboard Charge Ordering in Alkali-doped Iron Selenides $R$${}_{1-x}$Fe${}_{2-y}$Se${}_2$
• Phase co-existence and structured diffuse scattering seen by X-ray 3D mapping of reciprocal space for Cs0.8Fe1.6Se2

Cited by in corpus (4)

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• Formation of single-phase disordered CsxFe2-ySe2 at high pressure