Block Spin Ground State and Three-Dimensionality of(K,Tl)yFe1.6Se2

2011/02/28 by Chao Cao, Jianhui Dai · 5 citations
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #Antiferromagnetism #Atomic physics #Block (permutation group theory) #Combinatorics #Condensed matter physics #Electronic structure #Ground state #Inorganic Chemistry and Materials #Iron-based superconductors research #Magnetic moment #Materials science #Mathematics #Physics #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevlett.107.056401

published as Phys. Rev. Lett. 107, 056401 (2011) · Magnetic coupling constants double checked, journal ref. added

openalex publication_date 2011/07/27 · arxiv created 2011/07/28 · arxiv updated 2015/03/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The magnetic properties and electronic structure of (K,Tl)_yFe_1.6Se₂ is studied using first-principles calculations. The ground state is checkerboard antiferromagnetically coupled blocks of the minimal Fe₄ squares, with a large block-spin moment \ensuremath∼11.2\ensuremathμ_B. The magnetic interactions could be modeled with a simple spin model involving both the inter- and intrablock, as well as the nearest-neighbor and next-nearest-neighbor couplings. The calculations also suggest a metallic ground state except for y=0.8 where a band gap \ensuremath∼400--550 meV opens, showing an antiferromagnetic insulator ground state for (K,Tl)_0.8Fe_1.6Se₂. The electronic structure of the metallic (K,Tl)_yFe_1.6Se₂ is highly three dimensional with unique Fermi surface structure and topology. These features indicate that the Fe-vacancy ordering is crucial to the physical properties of (K,Tl)_yFe_2\ensuremath-xSe₂.

Citations

• Crystal Structure and Antiferromagnetic Order inNdFeAsO1−xFx(x=0.0and 0.2) Superconducting Compounds from Neutron Diffraction Measurements
• Projector augmented-wave method
• From ultrasoft pseudopotentials to the projector augmented-wave method
• Superconductivity at 25 K in hole-doped (La 1-x Sr x )OFeAs
• The superconductivity at 18 K in LiFeAs system
• Ab initiomolecular dynamics for liquid metals
• Maximally localized Wannier functions for entangled energy bands
• High-temperature superconductivity in iron-based materials
• Thorium-doping–induced superconductivity up to 56 K in Gd 1−x Th x FeAsO
• Superconductivity at 38 K in the Iron Arsenide(Ba1−xKx)Fe2As2

Cited by

• Magnetic phase diagram of an extendedJ1−J2model on a modulated square lattice and its implications for the antiferromagnetic phase of KyFexSe2
• Effective tight-binding model for the iron-vacancy-orderedAyFe1.6Se2
• Magnetic state of K0.8Fe1.6Se2from a five-orbital Hubbard model in the Hartree-Fock approximation
• Magnetic Resonant Mode in the Low-Energy Spin-Excitation Spectrum of SuperconductingRb2Fe4Se5Single Crystals
• Exploration of iron-chalcogenide superconductors

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• Density functional study of the overdoped iron chalcogenideTlFe2Se2withThCr2Si2structure
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• Coexistence of localized and itinerant magnetism in newly discovered iron-selenide superconductor LiFeO2Fe2Se2