Abstract
Electronic states of the CoO2 plane in Nax CoO2 are investigated on the basis of the triangular lattice 11-band d-p model by using the second order perturbation (SOP) and the random phase approximation (RPA). Due to the effect of the in-plane ferromagnetic fluctuations enhanced for 0.6 ≲ x ≲ 0.75, the quasiparticle dispersion near the Γ-point is strongly reduced to yield an almost flat dispersion just above the fermi level. With increasing x, the electronic specific heat coefficient γ increases towards the critical doping xc ∼ 0.75 above which the in-plane ferromagnetism takes place. We also find that the six small hole pockets near the K-point are stabilized due to the electron correlation effect within both the SOP and the RPA.
Original language | English |
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Pages (from-to) | 3317-3320 |
Number of pages | 4 |
Journal | Journal of Physics and Chemistry of Solids |
Volume | 69 |
Issue number | 12 |
DOIs | |
Publication status | Published - 2008 Dec |
Externally published | Yes |
Keywords
- A. Metals
- A. Oxides
- D. Magnetic properties
- D. Specific heat
- D. Thermodynamic properties
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics