Electronic Correlations in CoO2, the Parent Compound of Triangular Cobaltates

Abstract

A 59Co NMR study of CoO2, the x=0 end member of AxCoO2 (A = Na, Li...) cobaltates, reveals a metallic ground state, though with clear signs of strong electron correlations: low-energy spin fluctuations develop at wave vectors q different from 0 and a crossover to a Fermi-liquid regime occurs below a characteristic temperature T*~7 K. Despite some uncertainty over the exact cobalt oxidation state n this material, the results show that electronic correlations are revealed as x is reduced below 0.3. The data are consistent with NaxCoO2 being close to the Mott transition in the x -> 0 limit.

4 pages, submitted

References in corpus (7)

• Mott transition in Kagomé lattice Hubbard model
• Doping effects on the electronic and structural properties of CoO2: An LSDA+U study
• Dynamical mean field study of the Mott transition in the half-filled Hubbard model on a triangular lattice
• Na content dependence of superconductivity and the spin correlations in Na_{x}CoO_{2}\cdot 1.3H_{2}O
• Electronic Properties of the Hubbard Model on a Frustrated Triangular Lattice
• Stoichiometric oxygen content in NaxCoO2
• Na${}_x$CoO${}_2$ in the x -> 0 Regime: Coupling of Structure and Correlation effects

Cited by in corpus (8)

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• Spin correlations and cobalt charge states: A new phase diagram of sodium cobaltates
• Phase Diagram of Na${}_x$CoO${}_2$ Studied by Gutzwiller Density Functional Theory
• Correlation effects on the doped triangular lattice in view of the physics of sodium-rich Na${}_x$CoO${}_2$
• Spin polaron theory for the photoemission spectra of layered cobaltates
• Electrochemical synthesis and properties of CoO2, the x = 0 phase of the AxCoO2 systems (A = Li, Na)
• Vertex Corrections and the Korringa Ratio in Strongly Correlated Electron Materials