In-plane antiferromagnetism in Na_0.5CoO₂ induced by Sb_Co dopants

2012/11/26 by Assadi, M. H. N., Li, S., Zheng, R. K. +2
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)

paper · doi:10.48550/arxiv.1211.6167

Abstract

Na_xCoO₂ has a fascinating and complex magnetic phase diagram that can be further manipulated by doping. Here, we investigated the effect of electron doping on the magnetic coupling among Co⁴⁺ ions in Na_xCoO₂ using density functional theory based on Hartree-Fock hybrid functional. We found that electron doping through substitutional Sb_Co dopants flip the in-plane ferromagnetic coupling among Co⁴⁺ ions in the undoped compound to antiferromagnetic. Electron doping through interstitial Cu_Int, however, does not have a similar effect as Cu_Int dopant leaves the compound ferromagnetic, just like the case of the undoped compound. The results demonstrate the critical dependence of magnetic phase in Na_0.5CoO₂ on the dopant and its incorporation site.

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