Effects of local oxygen distortions on electronic structures of Na$_{x}$CoO$_{2}$

N. Jun; G. -M. Zhang

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arXiv · cond-mat/0305423

Effects of local oxygen distortions on electronic structures of Na$_{x}$CoO$_{2}$

N. Jun·G. -M. Zhang

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Abstract

By using pseudopotential method with local spin density functional approximation, the electronic band structures of Na$_{x}$CoO$_{2}$ are calculated for $x=0.25$, 0.5, 0.75, and $x=1$ in the presence of the structure relaxations. As increasing Na content, the hybridization between cobalt and oxygen orbitals is decreased, and a phase transition is predicted from a wide-band ferromagnetic to a narrow band paramagnetic metals. The itinerant ferromagnetism is strongly suppressed by the local distortions of the oxygens around the cobalts. Moreover, straining the CoO$_{2}$ layers corresponding to the hydrated superconductor Na$_{0.35}$CoO$_{2}\cdot $1.3H$%_{2}$O strongly enhances both the hybridization and ferromagnetism.

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N. Jun, G. -M. Zhang. 2003-09-01. Effects of local oxygen distortions on electronic structures of Na$_{x}$CoO$_{2}$. https://arxiv.org/abs/cond-mat/0305423

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