New electronic orderings observed in cobaltates under the influence of misfit periodicities

Abstract

We study with ARPES the electronic structure of CoO2 slabs, stacked with rock-salt (RS) layers exhibiting a different (misfit) periodicity. Fermi Surfaces (FS) in phases with different doping and/or periodicities reveal the influence of the RS potential on the electronic structure. We show that these RS potentials are well ordered, even in incommensurate phases, where STM images reveal broad stripes with width as large as 80Å. The anomalous evolution of the FS area at low dopings is consistent with the localization of a fraction of the electrons. We propose that this is a new form of electronic ordering, induced by the potential of the stacked layers (RS or Na in NaxCoO2) when the FS becomes smaller than the Brillouin Zone of the stacked structure.

References in corpus (17)

• Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)
• Large enhancement of the thermopower in Na${}_x$CoO${}_2$ at high Na doping
• Patterning of sodium ions and the control of electrons in sodium cobaltate
• Coupling between electronic and structural degrees of freedom in the triangular lattice conductor NaxCoO2
• Fermi Surface reconstruction in the CDW state of CeTe3 observed by photoemission
• Hidden magnetic transitions in thermoelectric layered cobaltite, [Ca${}_2$CoO${}_3$]${}_{0.62}$[CoO${}_2$]
• Low-lying quasiparticle states and hidden collective charge instabilities in parent cobaltate superconductors (NaxCoO2)
• NMR study of the magnetic and metal-insulator transitions in Na0.5CoO2: a nesting scenario
• Na Induced Correlations in Na${}_x$CoO${}_2$
• Spin correlations and cobalt charge states: A new phase diagram of sodium cobaltates
• Na ordering imprints a metallic kagome lattice onto the Co planes of Na2/3CoO2
• Interplay between magnetic properties and thermoelectricity in misfit and Na cobaltates
• Local moment, itinerancy and deviation from Fermi liquid behavior in Na${}_x$CoO${}_2$ for $0.71\le x\le 0.84$
• Comment on " Low-Lying Quasiparticle States and Hidden Collective Charge Instabilities in Parent Cobaltate Superconductors"
• Direct observation of strong correlations near the band insulator regime of Bi misfit cobaltates
• Spin fluctuations, magnetic long-range order and Fermi surface gapping in NaxCoO2
• Novel electronic structure induced by a highly strained oxide interface with incommensurate crystal fields

Cited by in corpus (4)

• 59Co NMR evidence for charge and orbital order in the kagome like structure of Na2/3CoO2
• Strong correlations enhanced by charge-ordering in highly doped cobaltates
• Synthesis of sodium cobaltate Na${}_x$CoO${}_2$ single crystals with controlled Na ordering
• Evolution of electron Fermi surface with doping in cobaltates