Interplay between Magnetism and Na concentration in $N{a}_{x}Co{O}_2$

Abstract

Through comprehensive density functional calculations, the crystallographic, magnetic and electronic properties of $N{a}_{x}Co{O}_2$ ($x$ = 1, 0.875, 0.75, 0.625 and 0.50) were investigated. We found that all Na ions in $NaCo{O}_2$ and $N{a}_{0.875}Co{O}_2$ share the basal coordinates with O ions. However, as $x$ decreases, some of Na ions move within the basal plane in order to reduce the in-plane Na$-$Na electrostatic repulsion. Magnetically, there was strong tendency for type A antiferromagnetism in the $N{a}_{0.75}Co{O}_2$ system, while all other Na deficient systems had a weaker ferromagnetic tendency. The results on magnetism were in excellent agreement with the experiments.

4 Pages, 3 Figures, 1 Supplementary PDF

References in corpus (4)

• Na atomic order, Co charge disproportionation and magnetism in Na${}_x$CoO${}_2$ for large Na contents
• 23Na NMR study of sodium order in NaxCoO2 with 22K Neel temperature
• Getting back to Na_xCoO_2: spectral and thermoelectric properties
• Selecting the suitable dopants: electronic structures of transition metal and rare earth doped thermoelectric sodium cobaltate

Cited by in corpus (3)

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• Na Site Doping a Pathway for Enhanced Thermoelectric Performance in $N{a}_{1-x}Co{O}_2$; The Case of Gd and Yb Dopants