Na ordering imprints a metallic kagomé lattice onto the Co planes of Na 2/3 CoO 2

2009/02/01 by H. Alloul, I. R. Mukhamedshin, T. A. Platova +1 · 44 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Cobalt #Crystal structure #Lattice (music) #Lattice constant #Magnetic and transport properties of perovskites and related materials #Metal #Topological Materials and Phenomena #cond-mat.str-el

paper · pdf · doi:10.1209/0295-5075/85/47006

published in Europhysics Letters (EPL) 85(4), 47006 (Institute of Physics) · 6 pages, 5 figures. Accepted at EPL (Europhysics Letters)

openalex publication_date 2009/02/01 · arxiv created 2009/02/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We report 23 Na and 59 Co nuclear magnetic (NMR) and quadrupolar resonance (NQR) studies for the x =2/3 phase of the lamellar oxide Na x CoO 2 , which allowed us to establish reliably the atomic order of the Na layers and their stacking between the CoO 2 slabs. We evidence that the Na + order stabilizes filled non-magnetic Co 3+ ions on 25% of the cobalt sites arranged in a triangular sublattice. The transferred holes are delocalized on the 75% complementary cobalt sites which unexpectedly display a planar cobalt kagomé structure. These experimental results resolve a puzzling issue by precluding localized moments pictures for the magnetic properties. They establish that the quasi-ferromagnetic properties result from a narrow band connecting a frustrated arrangement of atomic orbitals, and open the route to unravel through similar studies the electronic properties of the diverse ordered phases of sodium cobaltates.

Citations

• Electronic Model forCoO2Layer Based Systems: Chiral Resonating Valence Bond Metal and Superconductivity
• Coexistence of spin singlets and metallic behavior in simple cubicCsC60
• Spin correlations and cobalt charge states: Phase diagram of sodium cobaltates
• Na atomic order, Co charge disproportionation and magnetism in Na x CoO 2 for large Na contents
• Corporate Social Responsibility in the Regulatory Void - Does the promise hold? : self-regulation by business in South Africa and China
• Disorder, metal-insulator crossover and phase diagram in high-T c cuprates
• Fermi Surface Evolution and Luttinger Theorem inNaxCoO2: A Systematic Photoemission Study
• Charge Ordering, Commensurability, and Metallicity in the Phase Diagram of the LayeredNaxCoO2
• Bulk antiferromagnetism inNa0.82CoO2single crystals
• Cascade of Bulk Magnetic Phase Transitions inNaxCoO2as Studied by Muon Spin Rotation

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